Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02207294 1997-OS-28
'~', eJ'' fc
CAM-OPERATED TIMER BLADE SWITCHES
This application is related to the following co-pending applications filed on
the same day as this application entitled: Cam-Operated Timer, Cam-Operated
Timer Motor, Timer Camstack And Clutch, Cam-Operated Timer Pawl Drive, Cam-
Operated Timer Quiet Cycle Selector, Cam-Operated Timer Subinterval Switch,
and Cam-Operated Timer Test Procedure.
BACKGROUND
This invention relates to electrical circuit makers and breakers that are cam-
operated and more specifically to cantilever blade switches that engage a
camstack.
Cam-operated timers have been used for years to control the functioning of
appliances such as clothes washing machines, clothes dryers, and dishwashers.
Cam-operated timers used in appliances operate to control various appliance
functions in accordance with a predetermined program. Examples of appliance
functions that can be controlled by a cam-operated timer are: agitation,
washing,
spinning, drying, detergent dispensing, hot water filling, cold water filling,
and
water draining.
Cam-operated timers typically have a housing with a control shaft that
serves as an axis of rotation for a drum-shaped cam which may be referred to
as
a camstack. The camstack is connected to a drive system that is powered by an
electric motor to rotate the camstack. Camstack program profiles or blades
carry
the control information to operate blade switches. When the camstack rotates,
the
cam blades are engaged by switches that open and close in response to the cam
blade program. A knob is generally placed on the end of the control shaft
which
extends through the appliance control console for an appliance operator to
select
an appliance program.
Cam-operated timers are complex electro-mechanical devices having many
mechanical components inter-operating with each other under close tolerances.
One of the primary reasons that previous cam-operated timers have not been
assembled with a great deal of automation equipment is that the timer design
requires components to be assembled from a variety of axes. Manual assembly of
1
CA 02207294 1997-OS-28
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a complex device such as a cam-operated timer compared to automated assembly
can require more time and generate more quality defects. Automated assembly of
a cam-operated timer is desirable because automated assembly should be quicker
and have less quality defects than can be achieved economically with manual
assembly.
Some previous cam-operated timers have employed a metal housing to
contain timer components. The metal housing is typically formed from two or
more pieces of sheet metal that are fastened together to form a partially
enclosed
housing. A metal housing is typically required to be electrically insulated
from the
appliance and also typically requires connection of a grounding strap.
Additionally
a metal housing does not dampen the clicking sounds that can be generated by a
cam-operated timer's drive or cam followers. The partially enclosed housing
can
permit contaminates such as dust or lint to enter the cam operated timer and
interfere with electrical contacts or other mechanical components. Since the
metal
housing is typically formed from two or more pieces of metal, maintenance of
close component tolerances in relation to each other can be difficult. An
example
of a metal enclosure is disclosed in U.S. Patent No. 4,228,690 issued to Ring.
Some previous cam-operated timers designed for relatively simple
applications, such as a refrigerator freezer defrost timer, have employed a
plastic
housing to contain timer components. An example of a plastic enclosure for a
cam-operated timer that does employ a small camstack is disclosed in U.S.
Patent
No. 4,636,595 issued to Smock et al. An example of a plastic enclosure for a
cam-
operated timer that does not employ a camstack, but a pancake cam, is
disclosed
in U.S. Patent No. 4,760,2'19 issued to ~aniell et al.
Cam-operated timers are typically installed with fasteners in appliance
consoles where space can be very limited. A ground strap is usually run from
the
cam-operated metal housing to the appliance console. When a cam-operated
timer requires separate fasteners and a ground strap, it is difficult for an
appliance
manufacturer to automate installation of the cam-operated timer into their
appliance.
Previous cam-operated timers have been tested for proper operation by
connecting the timer switches to an electrical analysis device, directing
current
through the timer's motor, and allowing the gear train to drive the camstack
which
then operates the switches of the timer. If the electrical characteristics of
the timer
2
CA 02207294 2000-07-14
' match predetermined criteria, then the timer passes the test and is ready
for sale.
The amount of time that is required for a typical timer to complete a
revolution of its
camstack when driven by its motor and gear train is often in excess of one
hour.
This means that the testing time for previous cam-operated timers is also in
excess
of one hour.
SUMMARY
The invention provides a cam-operated timer that has a housing designed to
accept components assembled from a limited number of straight axes to simplify
assembly and permit greater automation of assembly. The invention also
provides a
cam-operated timer with components to be installed and positioned in relation
to
each other in a housing with integral molded mounting details, so there is
less
tolerance variation in the installation of timer components. Further, the
invention
provides a cam-operated timer housing that is formed from a material that
electrically insulates electrical components and encloses timer components to
provide protection from contaminates, and eliminates the need for a ground
strap.
The invention also provides a cam-operated timer which permits an appliance
manufacturer to install the cam-operated timer in an appliance without
separate
fasteners such as screws or nuts and bolts and without a ground strap. The
invention also provides a cam-operated timer having mounting fasteners
integral to
the timer housing, so the cam-operated timer can be installed in an appliance
console without the need for separate mounting hardware, and installation of
the
cam-operated timer in the appliance control console can be automated. The
invention also allows the camstack to be freely spun during a testing stage
following
substantial assembly of the timer so that the amount of time required for
timer
testing is greatly reduced.
The cam-operated timer apparatus and method that includes the above
aspects of the invention comprises the following. A housing having a base with
a
first open side, a second open side and details in the base pointing toward
the first
open side to accept cam-operated timer components. A cover enclosing the first
3
CA 02207294 1997-OS-28
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open side having details pointing toward the base to accept cam-operated timer
components. Timer components installed i~ the housing, comprising: a timer
drive mechanism received by the base details, a motor connected to the timer
drive mechanism and received by the base details in an axis perpendicular to
the
base, and a camstack having three or more program blades carried on a shaft,
driven for rotation by the timer drive mechanism, and received by details in
the
base in an axis perpendicular to the base.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a shows an appliance known in the prior art;
FBG. 1 b shows an assembled cam-operated timer in accordance with
the invention;
FIG. 2 shows a housing base for the cam-operated timer shown in
FIG. 1 b;
FIG. 3a shows the exterior view of the housing base shown in FIG. 2;
FIG. 3b shows the interior view of the housing base shown in FIG. 2;
FIG. 4a shows an exterior view of a first side cover to the housing
base shown in FIG. 2;
FIG. 4b shows an interior view of a first side cover to the housing base
shown in FIG. 2;
FIG. 5a shows an exterior view of a second side cover to the housing
base shown in FIG. 2;
FIG. 5b shows an interior view of a second side cover to the housing
base shown in FIG. 2;
FIG. 6 shows an exploded view of selected timer components and the
housing base shown in FIG. 2;
FIG. 7 shows an exploded view of a motor and gear train for the cam
operated timer shown in FIG. 1 b;
FIG. 8 shows an exploded view of a camstack for the cam-operated
timer shown in FIG. 1 b;
FIG. 9 shows an exploded view of blade switches and the second
side cover for the cam-operated timer shown in FIG. 1 b;
FIG. 10a shows the blade switches;
FIG. 10b shows a side view of the blade switches;
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CA 02207294 1997-OS-28
FIGs. 12a-b show a upper contact wafer assembly;
FIGs. 13a-b show a cam-follower wafer assembly; and
FIGs. 15a-b shows a lower contact wafer assembly.
DETAILED DESCRIPTION
Referring to FIGS. 1 b - 9, the cam-operated timer 52 incorporates principals
of Design For Manufacturing (DFM) and Design For Assembly (DFA). Under DFM
and DFA designing an apparatus is the first step in its manufacturing and
assembly. Design For Manufacturing involves considering how parts and
components will be manufactured when they are designed in order to reduce
manufacturing time, expense, waste, and improve quality. Generally parts can
be
manufactured better if their geometry is simple, there are as few parts as
possible,
and fasteners, retainers, guides, and bearings are integral to parts rather
than
separate components. Plastic parts can be manufactured better if they have
rounded corners, roughly consistent thickness, and draft angles to permit easy
extraction from molds. Use of plastic for parts can allow greater complexity
for a
single part than the use of metal thereby enabling parts reduction.
Design For Assembly (DFA) involves considering how parts will be
assembled into a product in order to reduce the number of parts and permit
easier
assembly of parts. An important aspect of DFA is to design parts that can be
handled and assembled more easily. Generally parts can be handled more easily
if parts can be assembled on a straight axis, there are only a few assembly
axes,
the part is oriented either parallel or perpendicular to the assembly axis,
the part
can only be assembled in the correct location, the target zone where the part
is to
be assembled is generous, the parts are radiused where they will contact other
parts during assembly to better guide the parts into the target, and the part
is
asymmetrical in both horizontal and vertical planes to permit automated
assembly
machines to better hold and orient parts. Design for assembly and design for
manufacturing are described in Machine Design, Design For Assembly, Penton
Education Division, 1100 Superior Avenue, Cleveland, Ohio 44114 (1984).
Referring to FIGS. 1a-9, an appliance 50 such as a clothes washing
machine, clothes dryer, and dishwasher often uses a cam-operated timer 52 to
control various appliance functions in accordance with a predetermined
program.
The cam-operated timer 52 will typically be mounted in an appliance console on
a
CA 02207294 1997-OS-28
Z
console mounting plate 51 that has a control shaft bore and mounting slots.
The
cam-operated timer 52 includes a housing, and timer components . The timer
components include a motor, a gear train 60 (see FIG. 19), a camstack 62, a
camstack drive 64, blade switches 66, a master switch, a quiet cycle selector
, and
a subinterval switch . A more detailed description of the housing and timer
components follow.
HOUSING
The housing includes a base 74, a first side cover 76, and a second side
cover 78. The housing base 74 has a first open side 80, a second open side 82,
a base platform 84 , base details, a base assembly detail 88, a base sealing
ridge
90, base first side cover fasteners 92, base second side cover fasteners 94,
base
plug rail 96, and a base mount. The first side cover 76 is installed over the
first
open side 80 of the housing base 74, and the second side cover 78 is installed
over the second open side 82 of the housing base 74. The base platform 84
carries the base details and provides a datum plane for orienting the housing
and
timer components . The housing is molded from a plastic such as a mineral
glass
filled thermoplastic such as polyester polybutylene terephthalate (PBT). The
housing base 74 is preferably molded to form a single piece of plastic with a
draft
angle of about 1.5° expanding toward the first open side 80.
The base details include base drive details, base motor details , base
camstack details , and base master switch details 148. The base details point
toward the first open side 80 to accept timer components , and the base
details
are orientated substantially perpendicular to the base platform 84. The base
details perform one or more of the following functions: locate timer
components
in the housing, retain timer components in the housing, and provide bearing
surfaces for movement of timer components . The base details reduce the need
for separate fasteners, connectors and bearings which can complicate assembly,
increase quality defects, and create tolerance stack-up problems. The base
details are generally either radiused or tapered on surfaces nearest the first
open
side 80 to provide a greater target area for the assembly of timer components
and to reduce the opportunity for timer components to improperly seat during
installation. Since the housing base 74 is preferably a single piece of
plastic and
the base details are integral to the base, assembly variations are greatly
reduced.
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CA 02207294 1997-OS-28
x
The use of molded base details reduces the number of parts required for the
cam-
operated timer 52.
The base drive details include a drive cam mount 102, a drive cam bore
104, a drive cam bore service mark 106, a drive spring mount 108, a
subinterval
pivot pin 110, a secondary drive pawl stop 112, a masking lever pivot pin 114,
delay spring support post 116, delay no-back spring seat 118, a delay rocker
pivot
pin 120, and delay wheel mount 122. The drive cam mount 102 inner diameter
provides a bearing for rotation of the camstack drive 64. The drive cam bore
104
permits visual inspection of the drive cam 606 by a service person to
determine if
the camstack drive 64 is rotating. The drive cam bore service mark 106 on the
outside of the base 74 permits a service person to relate camstack drive
operation
to camstack rotation. The drive spring mount 108 positions the drive spring
612
about 0.040 of an inch (0.102 cm) above the base platform 84 for proper
biasing
of the camstack drive 64. The subinterval pivot pin 110 provides the
subinterval
switch an axis on which to pivot. The secondary drive pawl stop 112 limits
movement of the camstack drive 64. The masking lever pivot pin 114 provides a
pivot axis for a camstack drive component 680. The delay spring support post
116 provides a location on the housing base 74 to connect a camstack drive
component. The delay no-back spring seat 118 provides a surFace to assist in
biasing a camstack drive component. The delay rocker pivot pin 120 provides a
pivot axis for a camstack drive component. The delay wheel mount 122 provides
an axis for rotation of a camstack drive component 672. The delay wheel mount
122 includes a delay wheel mount first bearing 124, a delay wheel mount draft
126, and a delay wheel second bearing 128. The delay wheel mount first bearing
124, the delay wheel mount draft 126, and the delay wheel mount second bearing
128 provide dual bearing surfaces to reduce the draft angle of the delay wheel
mount first bearing 124 and delay wheel mount second bearing 128 compared to
the overall draft angle of the delay wheel mount 122.
The base motor details include a motor shelf 132, motor pedestals 134,
motor pedestal ribs 136, and base motor fasteners 138. The motor shelf 132 and
motor pedestals 134 cooperate to locate the motor (see FIG. 7) about 1.19
inches
(3.023 cm) above the base platform 84. The motor pedestal ribs 136 vertically
locate a camstack drive component. The base motor fasteners 138 are
chambered to provide a larger target area to more easily align with the motor
7
CA 02207294 1997-OS-28
t
during installation and then after the motor is installed the base motor
fasteners
138 are heat staked to attach the motor to the housing base 74.
The base camstack details include a control shaft mount 142, a hub
opening 144, and camstack supports 146. The control shaft mount 142 outer
diameter serves as a bearing for rotation of the camstack 62. The hub opening
144 permits insertion of a camstack component during assembly of the cam-
operated timer 52. The camstack supports 146 carry the camstack 62 and are
radiused to reduce friction between the camstack supports 146 and locate the
camstack 62 about 0.360 of an inch (0.914 cm) above the base platform 84.
The base master switch details 148 include a rocker lifter pivot pin 150, a
rocker lifter retainer 152, a rocker lifter bearing 154, a switch lifter
offset 156, a
switch lifter pivot pin 158, a switch lifter retainer 160, a switch lifter
bearing 162, a
rocker support 164, a rocker cradle 166, and a lift bar channel 168. The
rocker
lifter pivot pin 150 and switch lifter pivot pin 158 locate master switch
components
on the base platform 84 and provide a pivot axis for master switch components.
The switch lifter offset 156 positions a master switch component about 0.055
of an
inch (0.140 cm) above the base platform 84 to provide clearance for the
subinterval switch. The rocker lifter bearing 154 and switch lifter bearing
162 are
raised portions of the base platform 84 that provide bearing surtaces to
reduce
friction during movement of master switch components. The rocker lifter
retainer
152 and switch lifter retainer 160 are hook-shaped and integral to the base
platform 84 to maintain proper alignment of master switch components in
relation
to the base platform 84. The rocker support 164 locates a master switch
component about 0.865 of an inch (2.197 cm) above the base platform 84, and
the
rocker cradle 166 provides a pivot axis and bearing surface for a master
switch
component. The lift bar channel 168 locates a master switch component and
provides an axis and bearing movement for the master switch component.
The base assembly detail 88 is an assembly mount that is used during
assembly of the cam-operated timer 52. The base assembly detail 88 is a
circular
bore in the housing base 74 that mates with automated assembly equipment such
as a palette-and-free assembly detail (not shown). During assembly of the cam-
operated timer 52, the base assembly detail 88 helps to locate and hold the
housing base 74 in an assembly palette for automated or manual assembly of the
cam-operated timer 52.
8
CA 02207294 1997-OS-28
"' r'~
The base sealing ridge 90 cooperates with the first side cover 76 to reduce
the opportunity for contamination to enter the housing between the base 74 and
first side cover 76. The base first side cover fasteners 92 cooperate with the
first
side cover 76 and are heat staked to attach the first side cover 76 to the
base 74.
The base second side cover fasteners 94 include a base second side cover pin
170 (see FIG. 3a), a base female wafer fastener 172 (see FIG. 2), and a base
female wafer ramp 174 that cooperate with second side cover 78 to attach the
second side cover 78 to the base 74. The base plug rail 96 aligns and guides
an
electrical plug (not shown) to mate with the blade switches 66 (see FIG. 9).
The
base plug rail 96 improves alignment of the electrical plug with the blade
switch 66
to improve electrical plug and reduce the opportunity for damage to the
electrical
connector and blade switches 66.
The base 74 is mounted to an appliance by first mounting tabs 176, a
second mounting tab 178, a locking pin support 180, and a screw mount 182
hereinafter collectively referred to as "the base mount". The base mount
cooperates with the first side cover 76 to attach the cam-operated timer 52 to
an
appliance console mounting plate 51 (see FIG. 1 a). The first mounting tabs
176
and second mounting tab 178 are radiused to ease insertion into appliance
console mounting slots. The second mounting tab 178 includes a second
mounting tab slot that receives a portion of the console mounting plate 51 to
secure the portion of the base nearest the second mounting tab slot to the
mounting plate. The locking pin support 180 cooperates with the first side
cover
76 to lock the cam-operated timer 52 on the mounting plate. The screw mount
182 is for a screw (not shown) that can be used as an additional means to
secure
the cam-operated timer 52 to the appliance console.
The first side cover 76 (see FIGs. 4a, 4b) includes first side cover fasteners
186, a first side cover lip 188, and a frst side cover locking pin 190. The
first
side also includes a camstack hub bore 192, a camstack hub bearing 194, a
cover
mounting recess 196, a detent follower channel 198. The first side cover 76
also
includes cover motor details, and cover master switch details as will be
described
below. The camstack hub bore 192 permits a portion of the camstack 62 to
extend through the first side cover 76. The camstack hub bearing 194 provides
both a rotational bearing and a thrust bearing for the camstack 62. The
camstack
hub bore 192 is not chambered to increase camstack hub bearing 194 strength.
9
CA 02207294 1997-OS-28
<t
The cover mounting recess 196 permits an appliance mechanical fastener such as
a screw (not shown) to have clearance without damaging the cam-operated timer
52. The detent follower channel 198 has a detent follower bore 200 and a
detent
spring pilot 202. The detent follower channel 198 and detent spring pilot 202
provide an axis for movement and assist in retaining timer components that
engage the camstack 62.
The cover motor details include cover gear arbor sockets 208, a cover
motor shaft socket 210, a cover spline connector bore 212, and a cover gear
train
partition 214. The cover gear arbor sockets 208 extend about 0.149 of an inch
(0.378 cm) from the first side cover 76 and have a chamber lead-in of about
45° to
increase the target area for assembly of the first side cover 76 over the
housing
base 74. The cover motor shaft socket 210 extends about 0.433 of an inch
(1.100
cm) from the first side cover 76 and also has a chamber lead-in of about
45° to
increase the target area for assembly of the first side cover 76 over the
housing
base 74. The cover gear train partition 214 serves to isolate most of the gear
train 60 in the housing.
The cover master switch details include a cover first lift bar guide 216, a
cover second lift bar guide 218, cover lift bar bearings 220, and a cover
rocker
retainer 222. The cover first lift bar guide 216 and the cover second lift bar
guide
218 cooperate to axially align a master switch component. The lift bar
bearings
220 provide bearing surfaces for smooth movement of a master switch
component. The cover rocker retainer 222 cooperates with the housing base
rocker support 164 to secure a master switch component in the housing base 74
when the first side cover 76 is installed.
The first side cover fasteners 186 include first side cover attachment bores
224, a cover female wafer fastener 226, and a cover female wafer ramp 228. The
first side cover attachment bores 224 receive complementary base first side
cover
fasteners 92 to align and attach the first side cover 76 to the base 74. The
first
side cover attachment bores 224 are chambered to provide a greater target area
when the first side cover 76 is attached to the housing base 74. The cover
female
wafer fastener 226 receives a complimentary fastener from the blade switches
66.
The cover female wafer ramp 228 provides a greater target area and eases
attachment of the complimentary fastener from the blade switches 66. Use of
plastic permits the first side cover 76 to be heat staked to the base 74 to
eliminate
CA 02207294 1997-OS-28
r ~ a
the need for separate fasteners such as screws or rivets. The first side cover
lip
188 extends around a portion of the periphery of the first side cover 76 to
create a
seal between the first side cover 76 and the base 74. The first side cover
locking
pin 190 engages a complementary fastener on an appliance console mounting
plate 51 to assist in securing the cam-operated timer 52 into an appliance
console.
The base locking pin support 180 cooperates with the first side cover locking
pin
190 to protect the first side cover locking pin 190 by limiting its flexing.
The second side cover 78 (see FIGs. 5a, 5b) includes, a wafer mount 230,
a plug connector 232, second side cover fasteners which are described below,
and second side cover assembly bores 236. The wafer mount 230 cooperates
with the second side cover assembly bores 236 to attach the blade switch 66 in
the second side cover 78. The wafer mount 230 includes a wafer shelf 238,
wafer
mounting bores 240, and wafer rivets 242 (see FIG. 9). The wafer shelf 238
aligns and stabilizes the blade switches 66 in the second side cover 78. Wafer
rivets 242 are then installed through the blade switches 66 and the wafer
mounting
bores 240 to secure the blades switches 66 into the second side cover 78. The
plug connector 232 has plug guides 244 and a ramped surface 246. The plug
guides 244 cooperate with the electrical plug (not shown) to properly align
the
electrical plug with the blade switches 66. When the electrical plug is seated
on
the blade switches 66, the vamped surface 246 engages the electrical plug to
lock
the electrical plug on the second side cover 78. The second side cover
fasteners
include a second side cover attachment bore 248, a second side cover base pin
250, and a second side cover ramp pin 252. The second side cover fasteners are
used to attach the second side cover 78 to the housing base 74 and first side
cover 76. The second side cover attachment bore 248 engages the base second
side cover pin 170 (see FIG. 3a) which is then heat staked to provide an
additional
means of attaching the second side cover 78 to the base 74. The second side
cover assembly bores 236 are used as an assembly aid when attaching the blade
switches 66 and as an assembly aid when attaching the second side cover 78 to
the housing base 74 and first side cover 76.
An advantage of having a plastic timer housing with all timer components
contained inside the plastic timer housing is that the cam-operated timer 52
is
electrically insulated from the appliance 50 eliminating the need for a ground
strap.
Another advantage of the electrically insulated plastic housing is that
integral
11
CA 02207294 1997-OS-28
i ~ u, }s
plastic attachments can easily be added to the plastic housing that are
designed
to cooperate with plastic attachments on the appliance control console to
permit
the cam-operated timer 52 to be snapped into the appliance 50 rather than be
attached with separate fasteners.
IDIOT~R
Referring to FIGS. 7 and 19-20b, the motor comprises a field plate 254, a
stator cup 256, a bobbin 258, a rotor 260, and motor terminals 262. The motor
transmits torque through the gear train 60 to rotate the camstack drive 64
(see
FIG. 6). The motor is an AC synchronous motor designed to operate on about
120 VAC at about 50-60 Hz to produce rotor rotation of about 600 RPM at a
torque of about 100 ounce-inches (0.072 KgM) measured at 1.0 R.P.M. A
separate enclosure for the motor is not necessary because the motor is
enclosed
by the housing thus double insulating the motor. The motor is placed at a mid-
level in the housing with the gear train 60 above the motor and the camstack
drive
below the motor. The motor terminals 262 permit the motor to be electrically
connected to the blade switches 66 when the second side cover 78, carrying the
blade switches 66, is attached to the housing.
The field plate 254 has stator poles 264, a rotor cavity 266, a field plate
bearing 268, stator cup slots 270, gear arbor bores 272, a field plate
terminal
block mount 274, and field plate attachment bores 276. The field plate stator
poles 264 are formed from material lanced and bent to form the rotor cavity
266.
Also by bending the stator poles 264 from rotor cavity material, the stator
poles
264 are curved toward the rotor cavity 266 which reduces the chance of the
rotor
260 becoming caught on a stator pole during installation. The field plate
bearing
268 is a sleeve bearing, integral to the field plate 254, that is extruded
toward the
housing base platform 84 to permit easier installation of a gear train
component.
The housingless motor is a factor that permits use of field plate bearing 268.
The field plate terminal block mount 274 has a first prong 278 and a second
prong 280 that engage the motor terminals 262 to align and support the motor
terminals. The field plate terminal block mount 274 aligns the motor terminals
262
in relation to the field plate 254. Since the field plate 254 is attached to
the
housing base 74, the motor terminals 262 are also aligned in relation to the
housing base 74 and the second open side 82. The field plate terminal block
12
CA 02207294 1997-OS-28
Z J L J1 l;
mount 274 supports the motor terminals 262 in both a plane parallel to the
housing base platform 84 and in a plane perpendicular to the housing base
platform 84. There is a space of about 0.050 of an inch (0.127 cm) between the
first prong 278 and the second prong 280 that the motor terminals 262 engage
to
strengthen the motor terminals 262 and to maintain a proper alignment angle
between the motor terminals 262 and the blade switches 66 attached to the
second side cover 78. The ends of the first prong 278 and second prong 280 are
tapered and engage the motor terminals 262 to substantially prevent axial
displacement of the motor terminals 262 when the second side cover 78,
carrying
the blade switches 66, is installed on the housing.
The field plate attachment bores 276 coincide with the base motor fasteners
138 (see FIG. 2) to align the field plate 254 in the housing base 74. The base
motor fasteners 138 are staked to the field plate attachment bores 276 to
secure
the field plate 254 to the housing base 74 to withstand about a 50.0 Ib.
(22.68 Kg)
pull-off force without loosening. The field plate 254 serves multiple
purposes: the
field plate 254 provides a means for attaching the motor subassembly to the
housing base 74; the field plate 254 carries the gear train 60; the field
plate 254
provides a bearing for a gear train component 260, and the field plate 254
provides a motor terminal mount. The field plate 254 is stamped from a low
carbon steel with good magnetic properties.
The stator cup 256 includes stator poles 282, a rotor shaft bore 284, a
bobbin terminal port 286, and stator cup tabs 288. The stator cup poles 282
are
formed from material outside the rotor cavity 266. The bobbin terminal port
286
provides an opening in the stator cup 256 for the portion of the bobbin 258
carrying the motor terminals 262 to extend through the stator cup 256. After
insertion, the stator cup tabs 288 are staked to the field plate stator cup
slots 270
to secure the stator cup 256 to the field plate 254. The stator cup 256 is
stamped
from a low carbon steel which is preferably the same material used for the
field
plate 254.
The bobbin 258 includes bobbin winding lugs 290, a bobbin reverse winding
post 292, bobbin stator notches 294, and magnet wire 296. The bobbin winding
lugs 290 are used to rotate the bobbin 258 when magnet wire 296 is wound onto
the bobbin 258. The bobbin reverse winding post 292 is used to reverse the
winding direction of the magnet wire 296, and has a radiused top to reduce the
13
CA 02207294 1997-OS-28
r
F~
probability of interference with winding. The bobbin stator notches 294 align
the
bobbin 258 with stator cup poles 264 when the bobbin 258 is installed in the
stator
cup prior to the stator cup 256 being staked to the field plate 254. The
bobbin
258 is preferably manufactured from a 30% glass filled nylon 6/6.
The magnet wire 296 is typically 43-48 gauge copper, and about 10,000 turns
are placed on the bobbin 258. The magnet wire 296 has ends that are skeined
with seven skeins for about five inches for added strength to reduce breaks
that
can occur when the magnet wire 296 is attached to the bobbin 258 and the motor
terminals 262. Winding of the bobbin 258 can be done in a single direction for
all
winding or some winding can be counter wound by using the bobbin reverse
winding post 292 to reverse the direction of winding. Counter winding permits
the
excitation level of the bobbin to be balanced with other factors such as rotor
inertia
and power consumption when using larger gauge, less expensive wire such as 40-
50 gauge wire. The number of counter-wound turns to adjust motor excitation E
as measured in ampere-turns is defined in terms of relation current I and the
number of turns of magnet wire N by the following formula: E = I (N FORWARD -
2N
REVERSE~~
The rotor 260 includes a rotor shaft 298, a rotor support 300, a molded
magnet 302, a no-back cam 304, and a rotor gear 306. The rotor shaft 298 is
inserted into the rotor shaft bore 284 and staked to the stator cup 256. The
top of
the rotor shaft 298 is slightly tapered to ease installation of the rotor 260
over the
rotor shaft 298. The rotor support 300 has a rotor support first end 301 and a
rotor support second end 303. The rotor support first end 301 is chambered to
fit
more easily over the rotor shaft 298. The rotor support second end 303 extends
beyond the rotor gear 306 to serve as a thrust bearing against the first side
cover
motor arbor socket. The molded magnet 302 is preferably an injection molded
polymer bonded ferrite. A synthetic lubricant such as Nye~ 723 is placed on
the
rotor shaft 298 to reduce friction. The rotor support is preferably molded
from a
liquid crystal polymer. The rotor gear 306 has ten teeth for 60 Hz
applications
twelve teeth for 50 Hz applications to produce about the same rotational speed
to
the first stage gear.
The motor terminals 262 include a motor terminal block 308 and motor
terminal wires 310. The motor terminal block 308 includes terminal block ribs
312,
a magnet wire guide 314, a magnet wire post 316, motor terminal sockets 318,
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terminal wire channels 320, center motor terminal guide 322, and side motor
terminal guides 324. The terminal block ribs 312 extend about 0.169 of an inch
(0.429 cm) from the motor terminal block 308 and engage the field plate
terminal
block mount 274 to secure the motor terminal block 308 to the field plate 254
and
align the motor terminal block 308 in relation to the housing base 74 and
second
open side 82. The bobbin 258 which is integral with the motor terminal block
308
also assists in securing the motor terminal block 308 to the field plate 254.
More
specifically, the terminal block ribs 312 cooperate with the field plate
terminal block
first prong 278 and second prong 280 to support and align the motor terminals
262
both in a plane parallel to the housing base platform 84 and in a plane
perpendicular to the housing base platform 84. Proper alignment and support of
the motor terminals 262 is necessary for the motor terminals 262 to mate with
the
target area of the blade switches during assembly of the blade switches 66
carried
in the second side cover 78.
The magnet wire guide 314 is a channel about 0.030 of an inch wide (0.076
cm) and about 0.060 of an inch deep (0.152 cm) to route the magnet wire 296
from the bobbin 258 to the motor terminal wires 296. The magnet wire post 316
cooperates with the motor terminal block 308 to create a channel to guide the
magnet wire 296 from the bobbin 258 to the motor terminal wires 296. The
magnet wire post 316 is radiused to reduce the opportunity for magnet wire 296
to
become snagged during connection of the magnet wire to the motor terminals
262.
The motor terminal sockets 318 receive the motor terminal wires 262 and
are circular with a diameter of about 0.0355 inch (0.0902 cm). The terminal
wire
channels 320 serve as an alignment aid during installation of the motor
terminal
wires 262. When the motor terminal wires 262 are installed in the terminal
wire
channels 320, the terminal wire channels 320 increase the rigidity of the
motor
terminal wires 262 and maintain parallel alignment of the motor terminal wires
262.
The terminal wire channels 320 are about 0.054 of an inch (0.137 cm) wide and
about 0.031 of an inch (0.079 cm) deep.
The center motor terminal guide 322 and side motor terminal guides 324
function to align the motor terminals 262 with the blade switches 66 when the
second side cover 78 is installed onto the housing base 74. The center male
guide 322 extends about 0.225 of an inch (0.572 cm) above the motor terminal
block 308 and narrows away from the motor terminal block 308 to ease insertion
CA 02207294 1997-OS-28
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into the blade switches 66. When the second side cover 78 is assembled onto
the
housing base 74, the center motor terminal guide 322 assists in locating the
motor
terminals 262 in relation to the blade switches 66. The side motor terminal
guides
324 extend about 0.100 of an inch (0.254 cm) and narrow away from the motor
terminal block 308 to ease insertion into the blade switches 66. When the
second
side cover 78 is assembled onto the housing base 74, the side motor terminal
guides 324 also assist in locating the motor terminals 262 in relation to the
blade
switches.
The motor terminal wires 262 include motor terminal wire coil ends 326 and
motor terminal wire blade switch ends 328. The motor terminal wires 262 are
preferably formed from a 0.031 inch (0.0787 cm) square phosphor bronze 510
alloy with a 0.003 inch (0.00762 cm) maximum radius on the corners that is pre-
tined with a solder. The motor terminal wire straight length is about 0.795 of
an
inch (2.019 cm), and both the motor terminal wire coil end 326 and the motor
terminal wire blade switch end 328 are cut with a 60° pyramid angle
swage. The
motor terminal wire coil end swage provides an insertion guide for inserting
the
motor terminals 262 into the motor terminal sockets 318. The motor terminal
wire
blade switch end swage provides an insertion aid to guide the motor terminal
wire
switch ends 328 into the blade switches 66 during installation on the second
side
cover 78. The terminal blade switch end 328 extends about 0.170 inches (0.432
cm) above the motor terminal sockets.
The motor terminal wires 262 are installed in the motor terminal sockets
318 as follows. The motor terminal wires 262 are inserted into the motor
terminal
sockets 318 prior to the bobbin 258 being wound with magnet wire 296. The
motor terminal wires 262 are secured in the terminal sockets 318 by
interference
between square motor terminal wires 262 and the round terminal sockets 318.
After the motor terminals 262 are inserted, the terminal blade switch ends 328
are
bent at about 90°, so the motor terminal wire switch ends are received
in the
terminal wire channels 320. The terminal wire channels 320 align and increase
the rigidity of the motor terminal wire switch ends. After the magnet wire is
attached to the motor terminal wire coil ends and soldered, the motor terminal
wire
coil ends 326 are bent at an acute angle with a roller to reduce damage to the
magnet wire and to prevent the coil ends from interfering with the first side
cover
detent follower channel 198.
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The motor is assembled before installation into the housing base 74 by
assembling motor components on a straight axis that is perpendicular to the
field
plate 254 using automated assembly equipment. Assembly of the motor begins by
staking the rotor shaft 298 to the stator cup rotor shaft bore 284. Gear train
components are then staked to the field plate gear arbor bores 272. After
staking,
the gear arbors 330 may be lubricated lightly to prevent corrosion. The motor
terminal wires 262 are inserted into the motor terminal sockets 318 and bent
so
that the motor terminal wire switch ends 328 are carried in the terminal wire
channels 320. The bobbin 258 is wound with wire 296 and the wire is attached
to
the motor terminal wire coil ends 326. The bobbin 258 is placed into the
stator
cup 256, and the stator. cup is attached to the field plate 254. When the
stator cup
256 is attached to the field plate 254, the terminal block ribs 312 engage the
field
plate terminal block mount 274, to align and secure the motor terminal block
308
to the field plate. The rotor shaft 298 is lubricated with a synthetic
hydrocarbon
such as Nye~ 723GR, and the rotor support 300 is placed over the rotor shaft
298. Gear train components are installed on the field plate 254 and lubricated
to
reduce noise during operation. The assembled motor is then placed on base
motor details and the base motor fasteners 138 are heat staked to secure the
motor module in place, and the rotor 260 is then placed over the rotor shaft
298.
GEAR TRAIN
Referring to FIGS. 7, 19 and 21, the gear train 60 includes gear arbors 330,
gears 332, and a spline connector 334. The gear train 60 transmits
approximately
100 inch ounces (0.072 KgM) of torque at 1.0 RPM as measured at the camstack
drive 64 from the motor and in the process reduces the rotational speed of the
motor and increases its torque. The gears 332 can be selected to change the
overall gear train ratio from about 250:1 to 1800:1 which represents
rotational
speeds from about 2.4 RPM to 0.3 RPM. Since the gear train 60 is located
inside
the housing, a separate housing for the gear train 60 is not required. The
gear
arbors 330 include a first stage gear arbor 336, a second stage gear arbor
338, a
third stage gear arbor 340, and a fourth stage gear arbor 342. The gear arbors
330 are staked to the motor field plate gear arbor bores 272. When the motor
subassembly is installed in the housing base 74 and the first side cover 76 is
attached to the housing base 74, the cover gear arbor sockets 208 engage the
17
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gear arbors 330 to help retain and maintain proper gear arbor alignment. The
gear arbors 330 are about 0.590 of an inch (1.499 cm) long and manufactured
from hardened steel. Once installed, the gear arbors 330 are coated with a
lubricant to reduce corrosion.
The gear train is divided into first level gears, second level gears, and
third
level gears. The gears 332 include a first stage gear 344, a second stage gear
360, a third stage gear 372, a fourth stage gear 384, and an output gear 396,
all
manufactured from a material such as acetal copolymer. Each of the gears 332
has a pinion gear and an outer gear. The gears 332 have an involute spline
profile
to provide more radiused surfaces for meshing than in some other types of
profiles. The gears 332 are also configured with a predetermined amount of
backlash to facilitate meshing, and the gears 332 are permitted to cant
slightly
when on the gear arbors 330 to facilitates meshing. The first level gears,
second
level gears and third level gear are constructed on three different meshing
levels,
a lower level, a middle level, and an upper level, so that the gears can be
installed
in some gear train configurations with only two gears meshing at a time during
assembly. Assembly of the gear train 60 with only two gears meshing at a time
is
easier and less complicated than assembly of gear train 60 requiring more than
two gears to mesh at a time. In other gear trains the third stage gear 372 may
be
required to mesh a total of three gears during assembly, i.e., the third stage
gear
372 may be required to mesh with both the second stage gear 360 and the fourth
stage gear 384 at the same time. The gears 332 are color coded for easy
identification with colors such as white, blue, green, and orange.
The first stage gear 344 has a first stage base thrust bearing (not shown), a
first stage no-back recess (not shown), a first stage no-back lever 350, a
first
stage bore 352, a first stage pinion 354, a first stage outer gear 356, and a
first
stage top thrust bearing 358. The first stage base thrust bearing 346 provides
a
surface for frictional contact with the field plate 254 when the first stage
gear 344
is installed on the first stage gear arbor 336. The first stage no-back recess
(not
shown) is a cavity to accept the first stage no-back lever 350. The first
stage no-
back lever 350 is attached to the outer diameter of the first stage thrust
bearing
and carried in the first stage no-back recess 348, so the first stage thrust
bearing
can still provide a surface for frictional contact with the field plate 254
once the
first stage no-back lever 350 is installed on the first stage gear 344. The
first
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stage no-back lever 350 is attached to the first stage gear 344 prior to the
first
stage gear 344 being installed on the first stage gear arbor 336. The first
stage
no-back lever 350 cooperates with the rotor no-back cam 304 to ensure the
motor
will only operate in one direction. The first stage no-back lever 350 is
preferably
manufactured from an acetal copolymer. The first stage bore 352 cooperates
with
the first stage arbor 336 to provide a low friction axis of rotation for the
first stage
gear 344. The first stage bore 352 has about a 45° chamber to provide a
greater
target area when the first stage bore 352 is placed over the first stage gear
arbor
336. The first stage outer gear 356 is driven by the rotor gear 306, and the
first
stage pinion 354 drives the second stage gear 360. The first stage top thrust
bearing 358 provides a frictional surface to contact the corresponding first
side
cover gear arbor socket when the cam-operated timer 52 is assembled. iNhen the
first stage gear 344 with attached first stage no-back lever 350 is installed
over the
first stage gear arbor 336, the first stage no-back lever 350 is oriented to
rotor
cavity side toward the motor terminals 262 for the motor to operate clockwise.
If
the first stage gear 344 with attached first stage no-back lever 350 is
oriented to
the rotor cavity side away from the motor terminals 262, the motor will rotate
counter-clockwise.
The second stage gear 360 has a second stage base thrust bearing 362, a
second stage bore 364, a second stage pinion 366, a second stage outer gear
368, and a second stage top thrust bearing 370. The second stage base thrust
bearing (not shown) provides a surface for frictional contact with the field
plate 254
when the second stage gear 360 is installed on the second stage gear arbor
338.
The second stage bore 364 cooperates with the second stage arbor 338 to
provide a low friction axis of rotation for the second stage gear 360. The
second
stage bore 364 has about a 45° chamber to provide a greater target area
when
the second stage bore 364 is placed over the second stage gear arbor 338. The
second stage outer gear 368 is driven by the first stage pinion 354, and the
second stage pinion 366 drives the third stage outer gear 380. The second
stage
top thrust bearing 370 provides a frictional surface to contact the
corresponding
second side cover gear arbor socket when the cam-operated timer 52 is
assembled.
The third stage gear 372 has a third stage base thrust bearing 374, a third
stage bore 376, a third stage pinion (hidden from view), a third stage outer
gear
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380, and a third stage top thrust bearing 382. The third stage base thrust
bearing
374 provides a surface for frictional contact with the field plate 254 when
the third
stage gear 372 is installed on the third stage gear arbor 340. The third stage
bore
376 cooperates with the third stage gear arbor 340 to provide a low friction
axis of
rotation for the third stage gear 372. The third stage bore 376 has about a
45°
chamber to provide a greater target area when the third stage bore 376 is
placed
over the third stage gear arbor 340. The third stage outer gear 380 is driven
by
the second stage pinion 366, and the third stage pinion drives the fourth
stage
outer gear 392. The third stage top thrust bearing 382 provides a frictional
surface to contact the corresponding third side cover gear arbor socket when
the
cam-operated timer 52 is assembled.
The fourth stage gear 384 has a fourth stage base thrust bearing (not
shown), a fourth stage bore 388, a fourth stage pinion (hidden from view), a
fourth
stage outer gear 392, and a fourth stage top thrust bearing 394. The fourth
stage
base thrust bearing provides a surface for frictional contact with the field
plate 254
when the fourth stage gear 384 is installed on the fourth stage gear arbor
342.
The fourth stage bore 388 cooperates with the forth stage arbor 342 to provide
a
low friction axis of rotation for the fourth stage gear 384. The fourth stage
bore
388 has about a 45° chamber to provide a greater target area when the
fourth
stage bore 388 is placed over the fourth stage gear arbor 342. The fourth
stage
outer gear 392 is driven by the third stage pinion, and the fourth stage
pinion
drives the output gear 396. The fourth stage top thrust bearing 394 provides a
frictional surtace to contact the corresponding first side cover gear arbor
socket
when the cam-operated timer 52 is assembled.
The output gear 396 has an output extension 398, an output base thrust
bearing 400, an output base lead-in (hidden from view), an output gear
disconnect
bearing 404, an output gear rotational bearing (hidden from view), an output
field
plate thrust bearing 408, an output gear spline bore 410, output gear splines
412,
output gear spline tips 414, an output spline connector groove 416, and an
output
cover thrust bearing 418. The output gear 396 functions to operate the drive
cam
606 (see FIG. 6) for rotation and retain and maintain proper alignment of some
camstack drive components. The output extension 398 extends through the motor
field plate 254 to retain and maintain proper alignment of some camstack drive
components. The output gear thrust bearing 400 engages the secondary drive
CA 02207294 1997-OS-28
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pawl 610 on the drive cam 606 to assist in locating and securing the camstack
drive 64 in the housing base 74. The output base lead-in has a larger diameter
than the drive cam top 630 to provide a larger target area for guiding the
output
gear 396 onto the drive cam 606. The output gear disconnect bearing 404
engages the drive cam disconnect bearing 631 to permit the output gear 396 to
rotate independently of the drive cam 606 until a spline connector 334 is
installed.
The output gear rotational bearing engages the field plate bearing 268 to
provide a
rotational axis for the output gear 396. The output field plate thrust bearing
engages the field plate 254 to properly space the output gear 396 in relation
to the
field plate 254 and provide a frictional surface for the output gear 396 to
contact
the field plate 254. The output spline bore 410 provides space to receive the
spline connector 334 and the output gear disconnect bearing 404 provides a
stop
to prevent the spline connector 334 from migrating into the output extension
398.
The output gear splines 412 provide a means to frictionally couple the output
gear
396 to the spline connector 334. The output gear spline tips 414 have about a
45°
point to assist in synchronizing the output gear 396 with the spline connector
334
during installation of the spline connector 334. The output spline connector
groove 416 assists in carrying the spline connector 334. The output cover
thrust
bearing 418 cooperates with the first side cover 76 to provide a frictional
surface
for contact with output gear 396 to assist in retaining the output gear 396 in
the
housing.
The drive connector 334, also referred to as a spline connector, includes a
spline connector lead-in 420, internal connector spline tips 422, internal
connector
splines 424, external connector spline tips 426, external connector splines
428,
spline connector locking fingers 430, and a spline connector assembly aid 432.
Without the spline connector installed, the output gear 396 can rotate on its
output
gear disconnect bearing 404 independently of the camstack drive 64 to permit a
test fixture to operate the camstack drive 64 to test operation of the blade
switches 66. Once the spline connector 334 is installed, the output gear 396
is
directly coupled to the camstack drive 64 for cam-operated timer operation.
The spline connector lead-in 420 extends beyond the internal connector
spline tips 422 and external connector spline tip 426 to provide a larger
target
area that does not require meshing to align the spline connector 334 with the
camstack drive 64 during installation. The internal connector spline tips 422
and
21
CA 02207294 1997-OS-28
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external connector spline fips 426 are tapered to about a 45° point to
ease
installation of the spline connector 334 by providing a larger meshing target
area.
The internal connector splines 424 cooperate with the camstack drive 64 to
provide a mechanical connection between the spline connector 334 and the
camstack drive 64. The external connector splines 428 cooperate with the
output
gear splines 412 to provide a mechanical connection between the spline
connector
334 and the output gear 396. The spline connector locking fingers 430 are
cantilever springs that create a larger outer diameter than the external
connector
splines 428. During installation through the first side cover spline connector
bore
212, the locking fingers contract to permit insertion through the first side
cover
spline connector bore 212 and then the locking fingers expand to capture the
spline connector 334 in the housing. When the spline connector 334 is
installed in
the output gear spline bore 410, the output spline connector groove 416
provides
clearance for the locking fingers to expand. The output gear disconnect
bearing
404 provides a stop for the spline connector lead-in 420 to contact to prevent
the
spline connector 334 from migrating into the output extension 398. The spline
connector assembly aid 432 cooperates with a tool during automated or manual
installation to facilitate insertion of the spline connector 334 through the
first side
cover 76 and into the output gear 396. The fit between the spline connector
334
and the output gear spline bore 410 is preferably toleranced to permit the
spline
connector 334 to float to reduce the opportunity for the camstack drive 64 to
bind
during temperature and humidity excursions.
The gear train 60 is not fully assembled until the motor is installed in the
housing base 74 and secured by heat staking to prevent damage to gears by high
temperature heat used in the staking procedure. Although, the first stage gear
with attached no-back lever is installed on the first stage arbor prior to the
motor
being installed into the housing base 74. A more detailed description of gear
train
assembly is provided in a subsequent section titled "Assembly Of The Cam-
Operated Timer".
CAMSTACK
Referring to FIGS. 8, 10a-18 the camstack 62 includes a camstack hub
434, camstack profiles 436, a control shaft 438, a clutch 440, and a cycle
selector
detent 442. The camstack 62 is drum shaped and carries information encoded on
22
CA 02207294 1997-OS-28
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camstack profiles 436 to open and close the blade switches 66 in accordance-
with
a predetermined appliance program. The camstack hub 434 cooperates with the
control shaft 438 to provide a rotational axis for the camstack 62. The
camstack
62 is driven for rotation by the camstack drive 64 which is connected through
the
gear train 60 to the motor. The camstack 62 can be manually rotated by an
appliance operator using the control shaft 438 to select an appliance cycle.
The
camstack 62 is preferably manufactured from a mineral or glass filed
polypropylene.
The camstack hub 434 includes a center web 444, a clutch cavity 446, a
clutch shelf 448, clutch fasteners 450, a hub extension 452, hub extension
grooves 454, a hub control dial positioned 456, a hub bore 458, a hub inner
bearing 460, a hub displacement stop 462, and a hub outer bearing 464. The
center web 444 connects the camstack hub 434 to the camstack profiles 436. The
clutch cavity 446 provides residential space to house the clutch 440
internally to
the camstack 62. The clutch shelf 448 extends around the perimeter of the
clutch
cavity 446 to form a stable platform to receive a clutch component. The clutch
fasteners 450 are heat staked after the clutch 440 is installed in the
camstack 62
to capture the clutch 440 and the control shaft 438 within the hub bore 458.
The
hub extension 452 extends through the first side cover camstack hub bore when
the camstack 62 is assembled in the cam-operated timer 52. The hub extension
452 also typically extends through an appliance console. The hub control dial
positioned 456 can carry a dial to communicate appliance cycle information to
an
appliance operator. The hub inner bearing 460 cooperates with the control
shaft
438 to provide a bearing for rotation of the camstack 62 on the control shaft
438.
The hub displacement stop 462 cooperates with the control shaft 438 to limit
the
travel of the control shaft 438 within the camstack 62 when the control shaft
is
indexed out to an extended position away from the housing base 74 by an
appliance operator. The hub outer bearing 464 cooperates with the control
shaft
438 to provide a second bearing for rotation of the camstack 62 on the control
shaft 438.
The camstack profiles 436 include switch program blades 466, a drive
surface 474, a detent blade 484, a camstack face 486, a delay profile 488, and
blade valleys 490. The switch program blades 466 carry appliance program
information to operate the blade switches 66 to make or break electrical
contacts
23
CA 02207294 1997-OS-28
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744 to switch appliance functions "on" and "off'. Examples of appliance
functions
that can be switched are hot and cold water valves, motor control circuits,
water
pump circuits, cam-operated timer motor control circuits, appliance motor
start
circuits, appliance motor run circuits, and to bypass circuits. The switch
program
blades 466 have an appliance program encoded on a top radius 468, a neutral
radius 470, a bottom radius 472. In cam-operated timer configurations without
the
optional master switch, the camstack profiles 436 can be configured to break
all
electrical contacts 744 of the blade switches 66 to turn "off' an appliance 50
such
as a dishwasher.
The drive blades 474 include a primary drive blade 476, a secondary drive
blade 478, a delay drive blade 480, and drive teeth 482. The primary drive
blade
476 and secondary drive blade 478 are engaged by the camstack drive 64 to
rotate the camstack 62. The delay drive blade 480 is used on cam-operated
timers that are configured with the optional feature of delay drive 604. The
primary drive blade 476, secondary drive blade 478, and delay drive blade 480
are
about 0.046 of an inch (0.117 cm) wide. The delay drive blade 480 is engaged
by
the camstack drive 64 to rotate the camstack 62 at a slower speed than when
the
camstack drive 64 engages the primary drive blade 476 and secondary drive
blade
478. The drive teeth 482 are located on the primary drive blade 476, secondary
drive blade 478, and delay drive blade 480 at predetermined intervals to
provide
incremental frictional surfaces for the camstack drive 64 to engage the
camstack
for rotation about the control shaft axis. Drive teeth 482 spacing may vary on
the
drive blades 474 to alter the rotational speed of the camstack 62 in the range
from
about 4.5° to 7.5° of camstack rotation for each camstack drive
increment.
Predetermined portions of the delay drive blade 480 will not have drive teeth
482
when the same predetermined portions of the primary drive blade 476 has drive
teeth 482 and vice versa. The camstack drive 64 keeps synchronized by having
drive teeth 482 on either the delay drive blade 480 or primary drive but not
both.
The delay profile 488 is located on the camstack interior diameter opposite
the
hub extension 452. The delay profile 488 contains predetermined information to
engage and disengage a component of the camstack drive 64. In bi-directional
applications, the delay profile 488 is configured to operate in either
direction.
The detent blade 484 is engaged by the cycle selector detent 442 to
provide the operator with either tactile or auditory feedback or both from the
cycle
24
CA 02207294 1997-OS-28
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it
selector detent 442 to more easily select an appliance function when the shaft
control knob 504 is rotated. The detent blade 484 has a profile that can be
varied
to correspond with appliance cycles. With a uni-directional camstack, the
detent
blade 484 can be configured with build-up torque prior to selection of a cycle
and
with an even greater exit torque prior to moving from the selected cycle. With
a
bi-directional camstack, the detent blade 484 is typically configured with
about the
same build-up torque as exit torque from a selection, so an appliance operator
is
given similar feedback during each direction of camstack rotation. The
camstack
face 486 can also be engaged by the cycle selector detent 442 to provide the
operator with either tactile or auditory feedback or both from the cycle
selector
detent 442 to more easily select an appliance function when the shaft control
knob
504 is rotated.
The following camstack profile configuration description is only one example
of how camstack profiles 436 may be arranged. For reference purposes, the
camstack switch program blades 466, drive blades 474, and detent blade 484 are
numbered from zero through fourteen starting from the switch program blade
opposite the camstack hub extension. The switch program blades 466 are the
even numbered camstack blades (0, 2, 4 . . .14). The primary drive blade 476
is
camstack blade number one, the secondary drive blade 478 is camstack blade
number three, the delay drive blade 480 is number five, and the detent blade
484
is number thirteen.
The control shaft 438 includes a shaft base end 492, a shaft bore 494 (see
FIG. 11), a shaft displacement stop 496, a shaft hub bearing 498, a shaft
control
end 500, a shaft locking pin 502, and a shaft control knob 504. The control
shaft
438 cooperates with the base control shaft mount 142, and camstack hub 434 to
provide a rotational axis for the camstack 62. The control shaft 438 is
axially
displaceable to a first depressed position and a second extended position. The
control shaft control knob 504 is used by an appliance operator to select an
appliance cycle and operate the master switch to turn the appliance 50 "on"
and
"off'. The control shaft control knob 504 is also used by an appliance
operator to
actuate the optional quiet cycle selector . The control shaft 438, with the
exception of the shaft locking pin 502 and shaft control knob 504, is
preferably
manufactured from a rigid plastic such as G.F. Nylon. The control shaft 438 is
an
option used on cam-operated timers with a master switch. If a control shaft
438 is
CA 02207294 1997-OS-28
i 'l
not used in a cam-operated timer configuration, such as a dishwasher, the
clutch
440 is also eliminated, and the camstack hub 434 is modified to cooperate with
the base control shaft mount 142 to provide a bearing for rotation of the
camstack
62. Also when a control shaft 438 is not used the shaft control knob 504 is
coupled to the hub extension 452 by the hub extension grooves 454.
The shaft base end 492 includes a shaft base end assembly detail 506 (see
FIG. 11 ), a shaft circular ramp 508, shaft base bearings 510, and shaft twist
lock
ribs 512. The base end assembly detail 506 provides frictional surtaces for a
manual or automated tool to rotate the control shaft 438 during assembly. The
shaft circular ramp 508 includes a shaft lift ramp 514, a shaft retention
latch 516,
and a shaft lift bearing 518. The shaft circular ramp 508 is used to by an
appliance operator to actuate the master switch and quiet cycle selector . The
shaft lift ramp 514 cooperates with the master switch and quiet cycle selector
to
convert axial displacement of the control shaft 438 to right angle
displacement of
master switch and quiet cycle selector components operating parallel to the
base
platform 84. The lift ramp is formed at about a 45° angle and has a
height of
about 0.140 of an inch (0.356 cm). The outer diameter of the lift ramp is
about
0.790 of an inch (2.007 cm).
The shaft retention latch 516 cooperates with master switch and quiet cycle
selector components to temporarily lock the master switch in the actuated
"off'
position and, if so equipped, temporarily lock the quiet cycle selector in the
actuated "select" position. The retention latch 516 is also ramp shaped and
forms
about a 150° angle which is also about a 30° reverse angle in
relation to the shaft
lift ramp 514. The shaft lift bearing 518 cooperates with master switch and
quiet
cycle selector components to provide a bearing for rotation between the
control
shaft 438 and the master switch when in the actuated "off' position and quiet
cycle
selector when in the actuated "select" position. The shaft lift bearing 518 is
about
0.010 of an inch (0.025 cm) wide flat surface parallel to the axial length of
the
control shaft 438.
The shaft base bearings 510 include a shaft base end bearing 522, a shaft
base internal bearing 524, a shaft base clutch bearing 526, and a shaft base
clutch bearing ledge 528. The shaft base end bearing 522 cooperates with
housing base 74 to provide a thrust bearing and indexing stop for the control
shaft
438 when the control shaft 438 is indexed in toward the housing base 74. The
26
CA 02207294 1997-OS-28
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shaft base internal bearing 524 cooperates with the housing base control shaft
mount 142 to locate the control shaft in the housing base 74 and to provide a
bearing for rotation of the control shaft 438. The shaft base clutch bearing
526
cooperates with the clutch 440 to provide a stable, low-friction bearing for
rotation
of the camstack 62 on the control shaft 438. The shaft base clutch bearing
ledge
528 retains a clutch component during assembly of the control shaft 438 and
clutch 440 to the camstack 62.
The shaft twist lock ribs 512 include shaft rib ends 530, a shaft rib
interruption 532, and a shaft rib base edge 534. The twist-lock ribs 512
provide a
structure to attach a clutch component to the control shaft 438. The twist-
lock ribs
512 are about 0.045 of an inch (0.114 cm) wide and the rib interruption 532 is
about 0.060 of an inch (0.152 cm) wide. The distance between the shaft rib
base
edge 534 and the shaft base clutch bearing 526 is about 0.070 of an inch
(0.178
cm). The shaft rib ends 530 are chambered at about 45° for easier
installation of
a clutch component. The shaft bore 494 extends through the entire length of
the
control shaft 438 and provides space for the shaft locking pin 502.
The shaft displacement stop 496 cooperates with the camstack hub
displacement stop 462 to control the distance the control shaft 438 can be
indexed
out, moved to an extended position, by an appliance operator to place the
master
switch in the unactuated "on" position and the quiet cycle selector in the
unactuated "operate" position. The displacement stop 496 provides a positive
stop
for the control shaft 438 at one of the strongest points in the camstack hub
434.
The displacement stop prevents the control shaft base end 492 from contacting
the clutch disk 560 to control displacement. The shaft hub bearing 498
cooperates with the camstack hub inner bearing 460 to provide a bearing for
rotation of the camstack 62 around the control shaft 438 when the camstack 62
is
driven for rotation by the camstack drive 64.
The shaft control end 500 includes shaft spring arms 536, shaft spring arm
barbs 538, shaft spring arm ribs 540, and a shaft control end stop 542. The
control end 500 typically extends through an appliance control console and
provides structure to attach the control knob 504 onto the control shaft 438.
The
shaft spring arms 536 are rectangular in shape with a taper and located about
180° apart on the shaft control end 500. The spring arms 536 extend
about 0.415
of an inch (1.054 cm) from the shaft control end stop 542. \/Vhen a control
knob is
27
CA 02207294 1997-OS-28
.e ~~
placed over the two spring arms 536 it boxes in the two spring arms to permit
both
clockwise and counter-clockwise rotation of the control knob by an operator.
The
shaft spring arm barbs 538 extend from the shaft spring arm ends to provide a
structure to lock the control knob on the control shaft 438 to prevent the
control
knob from being pulled off the control shaft 438 when an appliance operator
indexes the control shaft 438 out away from the appliance console. The shaft
control shaft end stop 542 provides a stable seat from the control knob on the
control shaft 438 and the shaft end stop 542 also limits movement of the
control
knob toward the shaft base end 492.
The shaft locking pin 502 includes a shaft locking pin knob groove 544, a
shaft locking pin stop 546, a shaft locking pin retention spring 548, and a
shaft
locking pin base end 550. The shaft locking pin 502 is inserted through the
base
hub opening 144 and into the camstack hub bore 458 to lock the control knob
504
onto the control shaft 438. The shaft locking pin knob groove 544 is designed
to
receive shaft spring arm ribs 540 to secure the shaft locking pin 502 in
position.
The shaft locking pin stop 546 extends from the shaft locking pin 502 to
interfere
with shaft bore 494 to limit movement of the shaft locking pin 502 toward the
shaft
control end 500. The shaft locking pin retention spring 548 also interferes
with the
housing base control shaft mount 142 to restrict movement of the shaft locking
pin
out of the shaft base end 492 prior to the control knob being installed on the
shaft
control end 500. The shaft locking pin base end 550 is a flattened surface
that
can be used as an assembly aid in automated or manual insertion of the shaft
locking pin 502 in the shaft bore 494. The shaft locking pin base end 550 also
permits gripping the shaft locking pin 502 for manual removal of the shaft
locking
pin 502 and control knob if the cam-operated timer 52 is removed from an
appliance console.
The shaft control knob 504 includes shaft knob spring arm slot 552, shaft
knob barb seats 554, and a shaft knob stop (hidden from view). The shaft knob
spring arm slot 552 receives the shaft spring arms 536 to permit the control
knob
to rotate the control shaft 438 bi-directionally. The shaft knob barb seats
554
receive the shaft spring arm barbs 538 to prevent the control knob from being
pulled off when the control shaft 438 is indexed out away from the base
platform
84. The shaft knob stop cooperates with the shaft control end stop 542 to
prevent
the knob 504 from sliding down the control shaft 438 when the control shaft
438 is
28
CA 02207294 1997-OS-28
c ~L:
indexed in toward the base platform 84. When the shaft locking pin 502 is
installed the shaft spring arms 536 are prevented from flexing inward to
maintain
the shaft spring arm barbs 538 engaged with the shaft knob barb seats 554.
The clutch 440 includes a ratchet 558 and a clutch disk 560. The clutch
couples the control shaft 438 to the camstack 62 when the control shaft 438 is
indexed inwardly toward the base platform 84 to allow an appliance operator to
select an appliance cycle. The clutch 440 decouples the control shaft 438 from
the camstack 62 when the control shaft is indexed outwardly away from the base
platform 84, so the appliance operator cannot rotate the camstack while the
camstack 62 is operating the blade switches. The clutch 440 can be configured
to
permit bi-directional or uni-directional rotation of the camstack when control
shaft
438 is indexed inwardly toward the base platform 84. When the clutch 440 is
assembled on the control shaft 438 and attached to the camstack 62 inside the
clutch cavity 446, the clutch 440 captures the control shaft 438 within the
camstack hub 434 to make assembly of the camstack 62 in the housing base
easier. The clutch 440 can be manufactured from a plastic such as acetal. The
clutch 440 is an option used on cam-operated timers with a control shaft 438.
The clutch ratchet 558 includes a ratchet base 562, a ratchet bore 564,
flexible fingers 566, a twist-lock latch 576, a twist lock stop 578, anti-
tangle
projections 580, and a ratchet assembly pin 582. The ratchet base 562 provides
a
stable platform to carry clutch ratchet components and defines the ratchet
bore
564. The ratchet bore 564 is sized to permit the ratchet 558 to be installed
over
the control shaft control end 500 and locate on the shaft base clutch bearing
ledge
528. The flexible fingers 566 include first direction ratchet springs 568,
second
direction ratchet springs 570, first direction ratchet teeth 572, and second
direction
ratchet teeth 574. The first direction ratchet springs 568 and second
direction
ratchet springs 570 are cantilever springs that extend from the ratchet base
562.
The first direction ratchet springs 568 and second direction ratchet springs
570
can flex to ease engagement of the ratchet 558 with the clutch disk 560 and
can
flex to permit the ratchet 558 to disengage from the clutch disk 560. The
first
direction ratchet teeth 572 are carried on the first direction ratchet spring
568 and
the second direction ratchet teeth 574 are carried on the second direction
ratchet
spring 570. Both the first direction ratchet teeth 572 and second direction
ratchet
teeth 574 are ramped shaped to facilitate engagement and disengagement from
29
CA 02207294 1997-OS-28
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the clutch disk 560.
The twist-lock latch 576 and twist-lock stop 578 cooperate with the control
shaft twist lock ribs 512 to secure the ratchet 558 onto the control shaft
438.
More specifically the twist-lock latch 576 engages the shaft rib interruption
532
and the twist-lock stop 578 engages the shaft rib edge 534'to secure the
ratchet
base 562 on the shaft base clutch bearing ledge 528. The twist-lock latch 576
is a
cantilever spring that compresses when rotated to engage the control shaft
twist
lock ribs 512 and expands when the twist-lock latch 576 engages a shaft rib
interruption 532. The twist-lock latch 576 has a ramped surface at about
45° that
extends from the ratchet base 562 about 0.025 of an inch (0.064 cm). The anti-
tangle projections 580 extend from the ratchet base 562 near the first
direction
ratchet teeth 572 and second direction ratchet teeth 574 to reduce the
opportunity
for more than one ratchet 558, for instance in a vibratory feeder bowl (not
shown),
to become tangled together and interfere with assembly. The ratchet assembly
pin 582 is asymmetric to the ratchet 558 and extends from the ratchet base 562
to
facilitate use of automated assembly equipment such as vibratory feeder bowls
and pick-and-place machines (not shown).
The ratchet springs 568, 570 can be either unidirectional ratchet springs or
bi-directional ratchet springs. The unidirectional ratchet springs include
first
direction ratchet teeth 572. The bi-directional ratchet springs include both
first
direction ratchet teeth 572 and second direction ratchet teeth 574. When the
control shaft 438 is rotated in a direction to cause the clutch 440 to slip,
the
ratchet teeth disengage from the clutch 440 and then the ratchet teeth are
biased
to re-engage with the clutch 440. The first direction ratchet teeth 572 and
the
second direction ratchet teeth 574 are spaced so that all first direction
ratchet
teeth 572 and all second direction ratchet teeth 574 engage the clutch disk
560
simultaneously. Both the unidirectional ratchet teeth and the bi-directional
ratchet
teeth have ratchet ramps of about a 45° ramp that extends from the
surtace of the
clutch ratchet 558 about 0.048 of an inch (0.122 cm). With unidirectional
ratchet
teeth, rotation toward the ratchet ramps causes slippage.
The clutch disk 560 has a clutch control shaft bore 584, a clutch control
shaft bearing 586, clutch slots 588, clutch mounting notches 590, and clutch
assembly pins 592 (see FIG. 14b). The clutch disk 560 cooperates with the
clutch
ratchet 558 to engage or disengage the control shaft 438 from the camstack.
The
CA 02207294 1997-OS-28
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clutch disk 560 also provides a bearing for the camstack hub 434 to rotate on
the
control shaft 438. The clutch control shaft bore 584 is about 0.574 of an inch
in
diameter (1.458 cm) and has a 45° chamber for a depth of about 0.030 of
an inch
(0.076 cm) and is sized to slide the control shaft 438 through the clutch
shaft bore
584 and stop on the circular ramp ledge 520. The clutch control shaft bearing
586
cooperates with the control shaft base external bearing to provide for
rotation of
the camstack hub 434 on the control shaft 438.
The clutch slots 588 are spaced so that when an operator indexes the
control shaft 438 to select an appliance function the clutch ratchet teeth
engage
the clutch slots 588 to permit rotation of the camstack 62. The clutch slots
588
are sized larger than the clutch ratchet teeth for less interterence when the
clutch
ratchet teeth engage the clutch slots 588. The clutch slots 588 have an outer
diameter of about 1.000 inch (2.540 cm) and an inner diameter of about 0.750
of
an inch (1.905 cm). Clutch slots 588 are positioned at about 12°
intervals around
the clutch disk 560. The clutch disk assembly pins 592 are an assembly aid
that
permits a clutch disk 560 to be aligned in a vibratory feeder bowl and track
assembly. The mounting notches 590 engage the clutch cavity clutch fasteners
450 to prevent the clutch disk 560 from rotating independently of the camstack
62.
The clutch disk 560 rests on the camstack clutch shelf 448 and two or more of
the
clutch fasteners 450 are heat staked to secure the clutch disk 560 to the
camstack
hub 434.
The camstack 62 is assembled as follows. First, the clutch disk 560 is
fitted over the control shaft 438 and is retained by the control shaft. Second
the
clutch ratchet 558 is also fitted over the control shaft 438 and is attached
to the
control shaft with a twist-lock fitting. The control shaft base end details
506 can
be used by automated equipment to rotate the control shaft 438 to install the
clutch ratchet 558. Once the ratchet 558 is attached to the control shaft 438,
the
clutch disk 560 is captured on the control shaft. Third, the control shaft
with
retained clutch disk 560 and attached ratchet 558 are installed in the
camstack 62.
During installation of the clutch disk 560 into the camstack 62, the clutch
disk
mounting notches 590 align with clutch features 450 to seat the clutch disk
560
into the camstack 62. Two or more of the clutch features 450 are heat staked
to
secure the clutch disk 560 in the camstack. When the camstack 62 is seated on
the control shaft mount 142, the base camstack supports 146 contact the clutch
31
CA 02207294 1997-OS-28
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disk 560 to position the camstack 62 about 0.100 of an inch (0.254 cm) above
the
base platform 84 to prevent the camstack 62 from interfering with timer
components . The camstack 62 is assembled before installation into the housing
base 74 by assembling camstack components on a straight axis that is parallel
to
the camstack hub 434 using automated assembly equipment which is discussed in
a later section entitled "Assembly Of The Cam-Operated Timer".
The cycle selector detest 442 is an option for the cam-operated timer 52
that provides a tactile feel to the appliance operated during cycle selection.
The
cycle selector detest 442 includes a detest follower 598 and detest spring
596.
The detest follower 598 engages the detest blade 484 (see FIG. 106) to
transmit
tactile feel to the appliance operator during cycle selection. The detest
spring 596
biases the detest follower 598 toward the camstack detest blade 484. The cycle
selector detest 442 is carried in the first side cover detest follower channel
198
with the first side cover detest spring pilot 202 engaging the detest spring
596,
and the detest follower 598 extending through the detest follower bore 200 to
engage the camstack detest blade 484. The cycle selector detest 442 is
installed
on a vertical axis into the first side cover detest follower channel 198 as
one of
the last timer components installed typically after the blade switches 66 have
been installed. The cycle selector detest 442 engages the camstack detest
blade
484 that has a profile that can be varied to correspond with appliance cycle.
The
detest follower 598 can be configured for unidirectional operation or bi-
directional
operation. When an operator rotates the control shaft 438 to select an
appliance
function, the operator receives either tactile or auditory feedback or both
from the
cam-operated timer 52, so the operator can more easily select an appliance
function.
The camstack 62 can be configured without a control shaft 438 and clutch
440. In that case, the hub extension 452 includes a hub control dial
positioned
configured to carry a control knob 504. In this configuration the clutch
cavity 446
is eliminated and a hub base bearing formed to engage the base control shaft
mount 142 'to provide an axis for rotation of the carnstack 62. In cam-
operated
timer configurations without the optional master switch, the camstack profiles
436
can be configured to break all electrical contacts 744 of the blade switches
66 to
turn "off' an appliance 50 such as a dishwasher.
32
CA 02207294 1997-OS-28
1 ly t ~#.
CAMSTACK DRIVE
Referring to FIG. 6, the camstack drive 64 includes a main drive and a
delay drive. The main drive includes a drive cam 606, a primary drive pawl
608, a
secondary drive pawl 610, and a drive spring 612. The motor transmits torque
through the output gear 396 to the drive cam 606 which in turn operates the
primary drive pawl 608 and secondary drive pawl 610 to rotate the camstack 62.
The drive cam 606, primary drive pawl 608, and secondary drive pawl 610 are
preferably manufactured from a rigid plastic with good wear characteristics
such
as glass-filled nylon. Assembly of the camstack drive 64 is described in a
subsequent section titled "Assembly Of The Cam-Operated Timer".
The drive cam 606 includes a drive cam base 614, a subinterval cam 616,
a separation shelf 618, a drive engagement cam 620, a drive lug 622, a delay
drive lug 624, a delay drive bearing 626, a secondary drive cam 628, and a
drive
cam top 630. The drive cam 606 is carried for rotation on the base drive cam
mount 102 and driven for rotation by the output gear 396 connected to the
drive
cam top 630. The drive cam 606 operates the camstack main drive as the
primary means to drive the camstack for rotation, and the delay drive as a
secondary means to drive the camstack for rotation when slower rotation of the
camstack is desired. The drive cam 606 through the subinterval cam 616 also
operates the subinterval switch to operate at least one blade switch 66
independent of the camstack 62.
The drive cam base 614 includes a drive base bearing 632, a drive interior
key 634, a drive thrust bearing 636. The drive base bearing 632 fits into the
base
drive cam mount 102 to provide for rotation of the drive cam 606. The drive
base
bearing 632 has an interior key 634 to permit alignment of the drive cam 606
during installation. An additional feature of the key 634 is to permit a
service
person to determine if the drive cam 606 is rotating since an operating timer
may
be so quiet that it could be difficult to determine if the motor is operating
the drive
cam 606. The drive thrust bearing 636 engages the side of the drive cam mount
102 nearest the first open side 80 to axially align the drive cam 606.
The subinterval cam 616 is engaged by the subinterval switch to operate at
least one blade switch 66 independently of the camstack 62. The separation
shelf
618 assists in capturing the subinterval switch in the housing base 74. The
subinterval cam 616 is sequenced with the drive stroke to engage and disengage
33
CA 02207294 1997-OS-28
r ,llu 1 f11
a switch from the camstack 62 unless masked.
The primary drive engagement cam 620 functions to control engagement of
the drive lug 622 with the drive lug track 640 of the primary drive pawl 608.
The
drive lug 622 cooperates with the drive lug track 640 to translate the drive
cam's
rotary motion to substantially linear motion of the primary driver pawl 608.
The
primary drive engagement cam 620 engages the engagement track 638 of the
primary drive pawl 608 and functions to disengage the drive lug 622 from the
drive
lug track 640 during predetermined periods. The drive lug 622 is hook shaped
and engages the drive lug track 640 to convert the rotary movement of the
drive
lug 622 to a lift and linear pulling motion of the primary drive pawl 608. The
delay
drive lug 624, also know as a delay drive cam, cooperates with the delay drive
to
convert the drive cam's rotary motion to a substantially linear motion to
operate
the delay drive.
The secondary drive cam 628 engages the secondary drive track 654 of the
secondary drive pawl 610 to convert the rotary movement of the secondary drive
cam 628 into a substantially linear motion. The secondary drive pawl 610
engages the camstack secondary drive blade 478 to prevent the primary drive
pawl 608 from reversing camstack rotation during the primary drive pawl's
return
stroke. The secondary drive pawl 610 is imparted with about a 0.006 inch
(0.015
cm) linear tangential pulling motion that advances the camstack slightly
during the
primary drive pawl's return stroke to improve the primary drive pawl's
engagement
of the primary drive blade 476 at the end of the primary drive pawl's return
stroke.
The drive cam top 630 includes a disconnect drive bearing 631, drive
splines 633, and drive spline tips 635. The drive disconnect bearing 631 is a
sleeve bearing that cooperates with the output gear disconnect bearing 404 to
disconnect the drive cam 606 from the output gear 396 during cam-operated
timer
testing before the spline connector 334 is installed. The drive splines 633
are
engaged by the spline connector 334 to couple the drive cam 606 to the output
gear 396. The drive spline tips 635 are tapered at about a 45° on each
side of the
splines to a point to permit easier installation of the spline connector 334.
By
having both the drive cam splines tips 635 tapered and the spline connector
internal connector spline tips 422 tapered, flat surfaces are eliminated that
could
butt against one another to complicate installation. Once the spline connector
334
is installed, the drive splines 633 are locked with the output gear splines
412 to
34
CA 02207294 1997-OS-28
connect the output gear 396 to the drive cam 606 for operation of the cam-
operated timer 52.
The primary drive pawl 608 has an engagement,track 638, a drive lug track
640, a first drive tip retainer 642, a second drive tip retainer 644, a
primary drive
tip 646 a drive foot 648, and a torsion spring shelf 650. The engagement track
638 cooperates with the drive engagement cam 620 to control engagement of the
drive lug 622 with the drive lug track 640. The drive lug track 640 cooperates
with
the drive lug 622 to translate the drive cam's rotary motion into linear
movement of
the primary drive pawl 608. The primary drive tip 646 engages the camstack
primary drive blade 476 at predetermined intervals with a tangential pulling
movement to rotate the camstack 62. Using a pulling motion reduces flexing of
the primary drive pawl 608 which reduces the probability that the primary
drive
pawl 608 will cam-out by losing engagement with the primary drive blade 476.
Camstack advance can be varied from about 4.5° to 7.5° of
camstack rotation
depending upon drive blade teeth 482 spacing. The first drive tip retainer 642
and
second drive tip retainer 644 extend below the primary drive tip 646 and
selectively engage the primary drive blade 476 to assist in keeping the
primary
drive pawl 608 in proper alignment with the camstack 62 during operation and
during functioning of the quiet cycle selector . The primary drive foot 648 is
used
to properly position the primary drive pawl 608 during assembly and to provide
means for retracting the primary drive pawl 608 for quiet cycle selection.
The secondary drive pawl 610 has spacing legs 652, a secondary drive
track 654, a third drive tip retainer 656, a fourth drive tip retainer i~58, a
secondary
drive tip 660, a secondary drive foot 662, and a drive spring contactor 664.
The
spacing legs 652 ride on the primary drive pawl 608 to properly position the
secondary drive pawl 610. The secondary drive track 654 has about a 0.003 of
an
inch (0.008 cm) offset eccentric. The secondary drive tip 660 engages the
secondary drive blade 478 with a tangential pulling movement to prevent the
primary drive pawl 608 from reverse rotating the camstack during the primary
drive
pawl's return stroke and to slightly rotate the camstack 62 during the primary
drive
pawl's return stroke. Using a pulling motion reduces flexing of the secondary
drive
pawl 610 which reduces the opportunity for the secondary drive pawl 610 to cam-
out by losing engagement with the secondary drive blade 478. The third drive
tip
retainer 656 and the fourth drive tip retainer 658 function to keep the
secondary
CA 02207294 1997-OS-28
~ ' a
~ ~ r rs~
drive pawl 610 properly aligned on the secondary drive blade 478. The
secondary
drive foot 662 assists in aligning the secondary drive pawl 610 during
installation
and also permits retraction of the secondary drive pawl 610 by the quiet cycle
selector . The drive spring contactor 664 off sets the drive spring 612 to
reduce
interference between the drive spring 612 and the primary drive pawl 608.
The drive spring 612 is a torsion spring and has a coil 666, a first spring
end 668, and a second spring end 670. The drive spring 612 is installed after
the
camstack 62 has been installed on the drive spring mount base detail with the
first
spring end 668 contacting the primary drive pawl spring ledge 650 and the
second
spring end 670 contacting the secondary drive pawl foot 662. The drive spring
612 provides about a 0.200 pound (0.090 Kg) biasing force to the primary drive
pawl 608 and the secondary drive pawl 610. The drive spring 612 is a coil
spring
rather than a leaf spring because a coil spring has advantages including
providing
a more constant force and each end of the coil spring can perform a biasing
function.
The delay drive includes a delay drive wheel 672, a delay camstack pawl
674, a delay ratchet pawl 676, a delay no-back pawl 678, and a masking lever
680. The delay drive is a second optional pawl drive system that is programmed
to operate at predetermined intervals in lieu of the camstack drive 64 to
greatly
reduce regular camstack rotational speed, in the range of 1,500 to 2,200
percent,
for functions such as in-cycle delay and delay-to-start. By reducing camstack
rotational speed during delay functions, switch program blade space can be
conserved. The delay drive 604 is activated and inactivated by the masking
lever
680 according to a predetermined program carried on the camstack delay profile
488. The delay drive 604 is synchronized with the camstack drive 64 so that
when the delay drive 604 is activated the angular location of the delay
ratchet
pawl 676 is known to permit more precise control of the delay drive in
relation to
the camstack drive 64. The delay drive could also be accomplished with
reduction
gears.
The delay drive wheel 672 has a delay wheel bore 682, a delay ratchet 684,
a delay pawl tip retainer 686, a delay cam bearing 687, and a delay drive lug
688.
The delay drive wheel bore 682 has a delay wheel first bearing 683, and a
delay
wheel second bearing 685. When the delay drive wheel bore 682 is installed on
the housing base delay wheel mount 122, the delay wheel first bearing 683 and
36
CA 02207294 1997-OS-28
x'
the delay wheel second bearing 685 cooperate with the housing base delay wheel
mount 122 to provide for more stabilized rotation than can typically be
provided
with a single bearing surface. The delay ratchet 684 is engaged by the delay
ratchet pawl 676 and delay no-back pawl 678 to incrementally rotate the delay
drive wheel 672. The delay pawl tip retainer 686 is a shelf to prevent the
delay
ratchet pawl 676 and delay no-back pawl 678 from moving out of alignment with
the ratchet 684 toward the first side cover 76. The delay cam bearing 687
engages the delay camstack pawl 674 to properly align the delay camstack pawl
674 in relation to the delay drive lug 688. The delay drive lug 688 engages
the
delay camstack pawl 674 to reciprocate the delay camstack pawl 674 in
predetermined fashion to engage the camstack delay drive blade 480.
The delay camstack pawl 674 has a delay camstack pawl alignment track
690, a delay camstack pawl lug track 692, a delay camstack pawl tip 694, a
delay
camstack pawl tip retainer 696, a delay camstack pawl spring post 698, a delay
camstack pawl foot 700, delay camstack pawl supports 702, and a delay camstack
pawl spring 704. The delay camstack pawl 674 is operated by the delay wheel
672 to engage the camstack delay blade 480 to drive the camstack for rotation
during predetermined periods of delay. During quiet cycle selection, the delay
camstack pawl 674 is engaged by quiet cycle selector components to disengage
the delay camstack pawl 674 from the camstack delay blade 480 to reduce noise
generated by the delay camstack pawl 674 when the camstack 62 is manually
rotated.
The delay camstack pawl alignment track 690 engages the delay cam
bearing 687 to properly align the delay camstack pawl lug track 692 in
relation to
the delay drive lug, 688. The delay camstack pawl lug track 692 is engaged by
the
delay drive lug 688 to convert the delay drive wheel rotary motion to a
substantially linear motion of the delay camstack drive pawl 674. The delay
drive
lug 688 cooperates with the delay camstack pawl lug track 692 to drive the
camstack 62 during about 90° of delay wheel rotation and retract the
delay
camstack pawl 674 during about 90° of rotation. Preceding both the
advance and
retraction there is a 90° dwell. When the camstack delay operates to
drive the
camstack 62 for rotation, the secondary drive pawl 610 continues to operate to
prevent the camstack 62 from reverse rotation during the time period when the
camstack delay drive 604 is operating.
37
CA 02207294 1997-OS-28
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The delay camstack pawl tip 694 engages the camstack delay blade 480 to
drive the camstack 62 for rotation at predetermined intervals. The delay
camstack
pawl tip retainers 696 assist in maintaining proper delay camstack pawl tip
694
alignment in relation to the camstack delay blade 480. The delay camstack pawl
spring post 698 provides a means for attaching the delay camstack pawl spring
704 between the delay camstack pawl 674 and the motor pedestal 134 to bias the
delay camstack drive pawl 674 toward the camstack 62 for contact with the
delay
drive blade 480. The delay camstack pawl spring 704 is an extension spring
with
delay camstack pawl spring loops 706 that are installed with the delay
camstack
pawl spring loops 706 oriented toward the housing base platform 84. One of the
delay camstack pawl spring loops 706 is connected to the motor pedestal 134
and
located by motor pedestal ribs 136 and the other delay camstack pawl spring
loop
706 is connected to the delay camstack pawl spring post 698 to bias the delay
camstack pawl 674 toward the camstack delay drive blade 480.
The delay camstack pawl foot 700 is used as a contact point with quiet
cycle selector components to lift the delay camstack pawl 674 away from the
camstack delay drive blade 480. The delay camstack pawl supports 702 contact
the motor stator cup 256 to serve as a thrust bearing to maintain the delay
camstack pawl 674 in proper alignment with the delay wheel 672 and to capture
both the delay camstack pawl 674 and delay wheel 672 in the housing base 74
once the motor is installed.
The delay ratchet pawl 676 has a delay ratchet pawl track 708, delay
ratchet pawl track extensions 710, a delay ratchet pawl tip 712, a delay
ratchet
pawl tip retainer 714, a delay ratchet pawl foot 716, and a delay ratchet pawl
spring post 718. The delay ratchet pawl 676 is driven by the drive cam 606 to
engage the delay wheel ratchet 684 to rotate the delay wheel 672. The delay
ratchet pawl track 708 engages the drive cam delay drive lug 624 to convert
the
drive cam rotary motion to reciprocate the delay ratchet pawl 676 for
engagement
with the delay wheel ratchet 684. The delay ratchet pawl tip 712 engages the
delay ratchet 684 to incrementally rotate the delay drive wheel 672. The delay
ratchet pawl tip retainer 714 cooperates between the delay wheel bearing 687
and
the delay drive wheel 672 to prevent the delay ratchet pawl 676 from moving
toward the first open side 80 and out of alignment with delay ratchet 684. The
delay ratchet pawl foot 716 cooperates with the housing base platform 84 to
38
CA 02207294 1997-OS-28
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prevent the delay ratchet pawl 676 from moving toward the housing base
platform
84 and out of alignment with the delay ratchet 684. The delay ratchet pawl
foot
716 also is contacted by the masking lever 680 to move the delay ratchet pawl
676 away from the delay ratchet 684 during predetermined periods when the
delay
drive 604 is to be inactivated. The delay ratchet pawl spring~ 720 is an
extension
spring that has one end connected to the delay ratchet pawl spring post 718
and
its other end connected to the base delay spring support post 116 to bias the
delay ratchet pawl tip 712 toward the delay ratchet 684.
The delay no-back pawl 678 has a delay no-back pivot 724, a delay no-
back tip 726, a delay no-back spring post 728, and a delay no-back spring 730.
The delay no-back pawl 678 functions to prevent the delay drive wheel 672 from
reversing rotation when driven by the delay ratchet pawl 676, and the delay no-
back pawl 678 functions to keep the delay drive wheel 672 stationary when the
delay ratchet pawl 676 is lifted away from the delay ratchet 684 when the
delay is
inactivated. The delay no-back pivot 724 is carried on the drive cam delay
drive
bearing 626. The delay no-back tip 726 engages the delay ratchet 684. The
delay no-back spring 730 is a compression spring with one end carried on delay
no-back spring post 728 and the other end carried on the base delay no-back
spring seat 118 to bias the delay no-back pawl 678 toward the ratchet wheel
684.
The delay masking lever 680 has a masking pivot bore 732, masking
bearings 734, a masking follower 736, and a masking lifter 738. The delay
masking lever 680 operates in accordance with a predetermined program encoded
on the camstack delay profile 488 to activate and inactivate the delay drive
604.
The masking lever 680 is mounted in the housing base 74 by placing the masking
pivot bore 732 over the base masking lever pivot pin 114, and the masking
bearing 734 contacting the housing base platform 84 to reduce friction when
the
masking lever 680 is operated. The masking follower 736 follows the camstack
delay profile 488 to move the masking lever 680 according to a predetermined
program. The masking lifter 738 contacts the delay ratchet pawl foot 716 in
response the camstack delay profile 488 to move the delay ratchet pawl tip 712
away from the delay ratchet 684 to inactivate the delay drive 604. By using
the
masking lever 680 to activate and inactivate the delay drive 604, a portion of
a
delay increment can be selected that is typically in the range from 95%-25%
for a
full delay increment.
39
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Blade Switches
Referring to FIGS. 9 - 15b, the blade switches 66 include a terminal end
740, a contact end 742, electrical contacts 744, lower contact wafer assembly
746,
cam follower wafer assembly 748, upper contact wafer assembly 750, blade
switch
terminals 752, motor terminal connectors 754, blade switch fasteners 756,
blade
switch bussing 758, an appliance motor start switch 760, and an appliance
motor
run switch 762. The blade switches 66 are carried by the second side cover 78
and are placed in working relationship to the camstack program blades 466 to
control appliance electrical circuits when the second side cover 78 is
attached to
the housing. The plastic molded components in the blade switches 66 are molded
from a plastic such as a P.B.T. polyester 15% G.F. / 20% M.F. unless otherwise
noted. The terminal end 740 is fixed and carried by the housing. The contact
end
742 is moveable and carries the electrical contacts 744.
The lower contact wafer assembly 746 (see FIGs. 15a, 15b) includes a
Bower contact wafer 764, lower contact wafer bores 766, lower switch blades
768,
lower blade electrical contacts 770, and blade spring supports 772. The lower
contact wafer 764 provides a housing for the lower switch blades 768 and is a
plastic such as a P.B.T. polyester 15% G.F. / 20% M.F. The lower contact wafer
bores 766 are chambered to increase the target zone for rivets during
assembly.
The lower switch blades 768 are insert molded into the lower contact wafer 764
at
about a 0° deflection angle. The lower switch blades 768 are
manufactured from
a metal that has good conductive and spring characteristics such as 260
cartridge
brass.
The lower blade electrical contacts 770 are manufactured from a metal tape
with good conductive and wear characteristics such as from a silver-cad oxide
alloy, a silver-cad oxide alloy cap on a copper alloy base, or a copper alloy.
The
lower electrical contacts 770 are attached to the lower switch blades 768 with
a
micro-resistance weld and then a light coining operation takes place to make
the
top surface of the lower electrical contact 770 slightly convex to compensate
for
tolerance variations in the attack closure angle of the mating lower blade
electrical
contacts 770 and cam-follower lower electrical contacts 798 (see FIG. 13b).
Lower blade electrical contacts 770 manufactured from metal tape require a
much
lighter coining operation than prior art cold headed or riveted contacts.
Thus,
CA 02207294 1997-OS-28
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lower blade electrical contacts 770 manufactured from metal tape result in
less
deformation of the lower switch blades 768 for better alignment and quality of
the
blade switches. The lower blade electrical contacts 770 can be configured as a
light duty contact that can switch loads up to about 1.0 Ampere, a medium duty
contact that can switch loads up to about 13.0 Amperes, or a heavy duty
contact
that can switch loads up to about 15.0 Amperes.
The blade spring supports 772 (see FIG. 9) include double cam-valley
riders 774, a single cam-valley rider 776, lower blade notches 778, a lower
blade
subinterval tab 780, lower blade supports 782 (see FIG. 15b), and lower blade
arc
barrier 784. The blade spring supports 772 are insert molded onto each lower
switch blade 768 and function to maintain proper alignment of the lower switch
blades 768 in relation to the camstack 62. ~uring insert molding of the blade
spring supports 772, the lower blade switch terminals are used to locate and
attach the blade spring supports 772, and the lower switch blades 768 have
details that assist in fixing the blade spring supports 772 to the lower
switch
blades 768. The lower blade support 782 in turn functions to maintain proper
alignment of the lower switch blades 768 in relation to the upper contact
wafer
assembly 750.
The double cam-valley riders 774 straddle program blades 466 contacting
camstack valleys 490 on both sides of a program blade 466. The single cam
valley rider 776 contacts one camstack valley 490 on one side of a program
blade
466. A single cam valley rider 776 is used on one of the endmost blade
switches
66 to reduce the overall width of the blade switches. A purpose of both the
double
and single cam valley riders 774, 776 is to maintain a constant distance
between
the lower contact blade 768 and the camstack 62. By maintaining a constant
distance between the lower switch blades 768 and the camstack 62, the blade
spring supports 772 compensate for tolerance variations in the camstack and
camstack wobble. Both the double cam-valley riders 774 and single cam-valley
riders 776 are about 0.032 of an inch (0.081 cm) wide. The program blade space
within the double cam-valley riders 774 is about 0.086 of an inch (0.217 cm).
The
lower blade notch 778 provides clearance for the cam-follower wafer assembly
748 to operate.
The lower blade subinterval tab 780 can be used with the optional
subinterval switch configured for single blade switch actuation. The lower
blade
41
CA 02207294 1997-OS-28
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subinterval tab 780 cooperates with the subinterval switch to maintain the
proper
alignment between the lower switch blade 768 and the subinterval switch . The
lower blade support 782 cooperates with the upper wafer assembly 750 to
maintain the-correct separation between the upper wafer assembly 750 and the
cam-follower wafer assembly 748 and the lower wafer assembly 746. The lower
blade support 782 is about Ø035 of an inch (0.089 cm) wide. The lower blade
arc
barrier 784 reduces arcing that can occur between the blade switches. The
lower
blade arc barrier 784 permits the blade switches 66 to be placed more closely
together than could be accomplished without a lower blade arc barrier 784.
The cam-follower wafer assembly 748 (see FIG. 13a, 13b) includes a cam-
follower wafer 786, cam-follower wafer bores 788, cam-follower switch blades
790,
cam-follower blade top surface 792, cam-follower blade bottom surface 794, cam-
follower blade angle forms 796 (see FIG. 10b), cam-follower lower electrical
contacts 798, cam-follower upper electrical contacts 800, cam-follower riders
802,
cam-follower lift tabs 804, cam-follower extended lift tabs 806, cam-follower
molding runners 808, and cam-follower blade subinterval tab 810. The cam-
follower wafer 786, cam-follower wafer bores 788, cam-follower switch blades
790,
cam-follower lower electrical contacts 798, and cam-follower upper electrical
contacts 800 are manufactured from materials and to conform to standards
similar
to their corresponding components in the lower wafer assembly 746 described
above with the following exceptions.
The cam-follower switch blades 790 are insert molded in the cam-follower
wafer 786 with a cam-follower blade angle form 796 of about 8.5°. The
cam-
follower blade angle form 796 is positioned about 0.022 of an inch (0.056 cm)
inside the cam-follower wafer 786 as measured from the cam-follower wafer edge
nearest the cam-follower riders 802. The cam-follower blade angle form 796
could
be positioned any distance inside the cam-follower wafer 786 and still achieve
the
advantage of encapsulating the cam-follower angle form. One advantage of
having the cam-follower angle form 796 located between the blade switch
terminals 752 and the cam-follower wafer edge nearest the cam-follower riders
802 is that force at the cam-follower lower electrical contacts 798 and cam-
follower upper electrical contacts 800 is more predictable because the
moveable
portion of the cam-follower switch blade 790 does not contain an angle form.
Another advantage of having the cam-follower angle form encapsulated in the
42
CA 02207294 1997-OS-28
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cam-follower wafer 786 is that cam-follower switch blade spring flex is more
consistent. An angle form is created in the cam-follower switch blade 790 by
exceeding the elastic limits of the cam-follower switch blade 790 to create a
permanent angle or angle form in the cam-follower switch blade 790. If the cam-
follower blade angle form 796 is placed on the moveable portion of the cam-
follower blade, material and manufacturing variances reduce the consistency of
cam-follower switch blade spring flex. Blade switch deflection is determined
where
y is deflection, W is load on a beam, x is a point on the beam where
deflection is
being calculated, E is modulas of elasticity of material, I is moment of
inertia of the
cross-section of the beam and p is beam length as expressed by the formula:
y 6 ~ (3e-~
The cam-follower lower electrical contacts 798 and cam-follower upper
electrical contacts 800 are attached to the cam-follower blade 790 in a
similar
fashion and have similar advantages as the lower blade electrical contacts 770
described above with the following differences and advantages. The cam-
follower
contacts 798, 800 are attached to the cam follower blade 790 in a staggered
relation to the cam-follower blade top surtace 792 and the cam-follower blade
bottom surface 794. More specifically the cam-follower upper contact 800 is
attached to the cam-follower blade top surface 792 between the cam-follower
rider
802 and the moveable contact end 742, and the cam-follower lower electrical
contact 798 is attached to the cam-follower blade bottom surtace 794 located
between the cam-follower rider 802 and the stationary terminal end 740. An
advantage of positioning the cam-follower upper contact 800 between the cam-
follower rider 802 and the moveable contact end 742 is that a greater
mechanical
advantage is provided to create faster and more accurate switching and more
contact movement than when the cam-follower upper contact 800 is placed
between the cam-follower rider 802 and the stationary terminal end 740. An
additional advantage of staggering the cam-follower lower electrical contacts
798
and cam-follower upper electrical contacts 800, both of which are manufactured
of
metal tape with a light coining operation to manufacture the cam-follower
lower
electrical contacts 798 and cam-follower upper electrical contacts 800 is that
the
cam-follower lower electrical contact 798 and cam-follower upper electrical
contact
43
CA 02207294 1997-OS-28
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800 can be different types rather than specifying both contacts to be the
highest
current rating of either the cam-follower lower electrical contact 798 or the
cam-
follower upper electrical contact 800. For instance, rather than using both
high
current contacts the cam-follower lower electrical contact 798 could be a low
current contact and the cam-follower upper electrical contact 800 could be a
high
current contact to reduce costs. Also by staggering the upper cam-follower
contact 800 and the lower cam-follower contact 798 on the cam-follower blade
790, electrical erosion of the cam-follower blade between the upper cam-
follower
contact and lower cam-follower contact is reduced because electrical arcing on
the
upper cam-follower contact 800 occurs at a different location on the cam-
follower
blade 790 than arcing on the lower cam-follower contact 798.
The cam-follower riders 802 are insert molded onto the cam-follower switch
blades 790 in a fashion similar to how the blade spring supports 772 are
insert
molded onto the lower switch blades 768 described above with the following
exception. The cam-follower molding runner 808 provides a path for plastic
during
insert two plate molding of the cam-follower riders 802, cam-follower lift
tabs 804,
and cam-follower extended lift tabs 806. The cam-follower riders 802 engage
the
switch program blades 466 to move the cam-follower switch blades 790 in
accordance with a predetermined program. The cam-follower lift surface is
engaged by the master switch to lift the cam-follower blades 790 away from the
lower switch blades 768 to break electrical contact. The cam-follower extended
lift
tabs 806 extend about 0.040 of an inch (0.102 cm) from the cam-follower lift
surface and are engaged by the master switch in quiet cycle selector
configuration
to lift the cam-follower riders 802 high enough to clear the switch program
blades
top radius 468 to prevent noise from being generated by the cam-follower
riders
802 during quiet cycle selector operation in addition to breaking electrical
contact
with the lower switch blades 768. The cam-follower blade subinterval tab 810
extends about 0.040 of an inch (0.102 cm) from the edge of the cam-follower
switch blade 790 and is engaged by the subinterval switch to operate a blade
switch.
The upper contact wafer assembly 750 (see FIGs. 12a, 12b) includes an
upper contact wafer 812, upper contact wafer bores 814, upper switch blades
816,
upper blade angle forms 818 (see FIG. 10b), upper electrical contacts 820,
upper
blade support tabs 822, upper blade support notches 824, and upper switch
blade
44
CA 02207294 1997-OS-28
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extensions 826. The upper switch blades 816, upper electrical contacts 820,
and
upper contact wafer 812 are manufactured from materials and conform to
standards similar to their corresponding components in lower wafer assembly
746
described above. The upper switch blades 816 are molded into the upper contact
wafer 812 at an upper blade angle form 818 of about 12° in a similar
fashion to
the cam-follower blade angle forms 796 described above.
The upper blade support tabs 822 contact the lower contact spring supports
772 so the upper electrical contacts 820 will maintain a constant distance air
gap
from the lower blade electrical contacts 770. The upper contact wafer assembly
component contacts the upper spring blade support about 0.180 of an inch
(0.457
cm) above the lower spring blade. The upper blade support tabs 822 are located
between the upper blade contact and the upper blade stationary end. A support
notch 824 is formed in the upper blade 816 to permit clearance of an adjacent
blade switch with an upper blade support tab 822. The upper switch blade
extensions 826 are engaged by the master switch or quiet cycle selector to
lift the
upper switch blades 816 to break electrical contact with the cam-follower
upper
electrical contacts 800.
The blade switch terminals 752 include blade switch alignment details 828
and blade switch terminal notches 830. The blade switch alignment details 828
can be blade switch bores that are used as an alignment detail during insert
molding of the lower contact wafer assembly 746, the cam-follower wafer
assembly 748, and the upper contact wafer assembly 750. The blade switch
bores 828 are engaged by a wafer mold pin to increase molding accuracy of the
blade switches 66 in the corresponding lower contact wafer 764, cam-follower
wafer 786, or upper contact wafer 812. The blade switch terminal notches 830
are
an assembly aid. An assembly fixture engages the blade switch terminal notches
830 during assembly of the blade switches 66 to properly align the lower
contact
wafer assembly 746, the cam-follower wafer assembly 748, and the upper contact
wafer assembly 750 in relation to the blade switch terminals 752. By aligning
the
lower contact wafer assembly 746, the cam-follower wafer assembly 748, and the
upper contact wafer assembly 750 in reference to the blade switch terminals
752,
more accurate blade switch alignment is achieved than alignment off a material
such as a plastic molding. The terminals are integral to the switch blades and
are
shaped to meet National Electrical Manufacturers Association (NEMA) standards
CA 02207294 1997-OS-28
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and to be accepted by a plug-type electrical connector.
The blade switch bussing 758 includes a horizontal bussing port 832, a first
vertical bussing port 834, a second vertical bussing port 836, bussing ridges
838,
bussing ridge motor connector slot 840, bussing pins 842, and a bussing cap
844.
Blade switch bussing 758 permits the making of permanent hard wire connections
between selected blade switch terminals 752 and provides a location for the
motor
terminal connectors 754 to bridge an electrical connection between the blade
switches 66 and the motor terminals 262. The horizontal bussing port 832
allows
selected adjacent blade switch terminals 752 on the lower contact wafer
assembly
746 or cam-follower wafer assembly 748, or upper contact wafer assembly 750 to
be electrically connected. On selected adjacent blade switch terminals 752
where
an electrical connection is not desired, the material connecting the adjacent
blade
switch terminals 752 is lanced to break the electrical connection. The
horizontal
bussing port 832 provides adequate space so that the material connecting the
adjacent blade switch terminals 752 that is lanced remains connected to the
blade
switches 66 to reduce manufacturing complications that can result from small
loose pieces of blade switch material. The first vertical bussing port 834
provides
an opening to insert bussing pins 842 to form electrical connections between
lower
switch blades 768 and upper switch blades 816. The second vertical bussing
port
836 provides an opening to insert bussing pins 842 to form electrical
connections
between cam-follower switch blades 790 and upper switch blades 816. The
bussing ridges 838 form slots to carry bussing pins 842. The bussing ridge
motor
connector slot 840 receives a motor terminal connector component to align and
secure the motor terminal connector component in the lower contact wafer 764.
The bussing pins 842 are used in the first vertical bussing port 834, the
second
vertical bussing port 836, and on the blade switch terminals 752 to
electrically
connect selected blade switch terminals 752. The bussing cap 844 electrically
insulates the bussing pins 842 used on blade switch terminals 752 from an
electrical connector (not shown) used on the blade switch terminals 752.
The motor terminal connectors 754 include a first motor connector 846, a
second motor connector 848, male motor connector guides 850, and a female
motor connector guide 852. The motor terminal connectors 754 cooperate with
the motor terminals 262 to electrically connect the blade switches 66 to the
motor
in a fashion that permits automated assembly of the blade switches 66 onto the
46
CA 02207294 1997-OS-28
r ~ ' r,' ~ ~ ;~r
housing along a single axis. The first motor connector 846 includes a first
motor
connector shaft tip 854, a first motor connector shaft 856, and a first motor
connector clip 858. The first motor connector shaft tip 854 is chambered at
about
45° and offset about 0.010 of an inch (0.0254 cm) toward the center of
the first
motor connector shaft 856 to guide both the first motor connector shaft tip
854 and
first motor connector shaft 856 into the appropriate first vertical bussing
port 834
during assembly. The edges of the first motor connector shaft 856 are bent to
avoid having opposing sharp edges that could cause jamming during assembly
and to strengthen the first motor connector shaft 856. The first motor
connector
shaft leading edges are chambered at about a 30° angle to further ease
insertion.
The first motor connector clip 858 is clothes pin shaped to create spring
pressure
for a good electrical connection with the motor terminal wire switch end 328.
The
second motor connector 848 includes a second motor connector shaft tip 860, a
second motor connector shaft 862, a second motor connector clip 864, and a
second motor connector shaft extension 866. The second motor connector shaft
tip 860, second motor connector shaft 862 and second motor connector clip 864
are similar to those previously described for the corresponding components of
the
first motor connector 846. The second motor connector shaft extension 866
engages the bussing ridge motor connector slot 840 to assist in locating and
securing the second motor connector clip 864.
The male motor connector guides 850 and female motor connector guide
852 are integral to the lower contact wafer 764 and engage the motor's center
motor terminal guide 322 and side motor terminal guides 324 to align the motor
terminal wire switch end with the first motor connector clip 858 and the
second
motor connector clip 864 when the blade switches 66 are installed on the
housing.
The blade switch fasteners 756 include wafer rivets 242, male wafer
fasteners 868, and male wafer fastener ramps 870. The wafer rivets 242 are
installed through the lower contact wafer bores 766, the cam-follower wafer
bores
788, the upper contact wafer bore 814, and the second side cover wafer
mounting
bore 240 to secure the blade switches 66 to the second side cover 78. The male
wafer fasteners 868 are formed by material from the lower contact wafer 764
and
the cam-follower contact wafer 786 and are engaged by the base female wafer
fastener 172 and cover female wafer fastener 226 to assist in securing the
blade
switches 66 with attached second side cover 78 to the housing base 74 and
first
47
CA 02207294 1997-OS-28
' w' . ~ ;.7
side cover 76. The male wafer fastener ramps 870 are chambered surfaces that
cooperate with the base female wafer ramp 174 and cover female wafer ramp 228
to increase the assembly target area and to serve as a guide during
installation of
the blade switches 66 with attached second side cover 78 onto the housing base
74 and first side cover 76.
The blade switches 66 are assembled before installation into the housing
base 74 by assembling blade switch components on a straight axis that is
perpendicular to the blade switch terminals 752 using automated assembly
equipment which is discussed in a later section entitled "Assembly Of The Cam-
Operated Timer". The upper wafer assembly 750 is stacked on top of the cam-
follower wafer assembly 748 and the lower wafer assembly 746 is stacked under
the cam-follower wafer assembly 748. An assembly fixture assists in properly
aligning the wafer assemblies. Additionally, the second side cover notches
help to
properly place the upper contact wafer assembly 750 in relation to the second
side
cover 78. Wafer rivets 242 are installed through the stacked upper wafer
assembly 750, cam-follower wafer assembly 748, lower wafer assembly 746, and
through the second side cover 78. The rivets securely attach the blade
switches
66 to the second side cover 78.
The blade switch terminal notches 830 are used to align the lower contact
wafer assembly 746, the cam-follower wafer assembly 748, and the upper contact
wafer assembly 750 during installation in the second side cover 78. The mating
surfaces of the lower contact wafer assembly 746, cam-follower wafer assembly
748 and upper contact wafer assembly 750 are substantially smooth to permit
the
mating surface to align according to the blade switch terminal notches 830 to
more
accurately align lower switch blades 768 with the cam-follower switch blade
790
with the upper switch blades 816.
48
